Homo sapiens diorama in Hall of Human Origins AMNH (NYC)

Homo ergaster (erectus?) diorama in Hall of Human Origins AMNH (NYC)

            The incredible story of our evolution from ape ancestors spans 6 million years or more, and features the acquirement of traits from bipedal walking, large brains, hairlessness, tool-making, hunting and harnessing fire, to the more recent development of language, art, culture and civilisation.            Darwin’s The Origin of Species, published in 1859, suggested that humans were descended from African apes. However, no fossils of our ancestors were discovered in Africa until 1924, when Raymond Dart dug up the “Taung child” – a 3-million to 4 million-year-old Australopithecine.            Over the last century, many spectacular discoveries have shed light on the history of the human family. Somewhere between 12 and 19 different species of early humans are recognised, though palaeoanthropologists bitterly dispute how they are related. Famous fossils include the remarkably complete “Lucy”, dug up in Ethiopia in 1974, and the astonishing “hobbit” species, Homo floresiensis, found on an Indonesian island in 2004.Read more: https://www.newscientist.com/article/dn9990-introduction-human-evolution/#ixzz6siK7sr9z

Eosimias

Notharctus

Purgatorius

Fossil Evidence

Some of the things we can determine from FOSSILS:Bipedal or quadrupedal? (Skull, knees, pelvis)
Based on geological surroundings: Approximately WHEN did these hominins live?
Location and movement can be estimated based on chemical signatures left in fossilized bone.
Morphology (characteristics of the hominin’s body)
Skulls (brain-size, brain features such as Broca’s Area)
Teeth (diet and species)
Diet (chemical “fingerprints” left in bones and teeth)
Age of individual (from size and development of bones)
Health of individual (bone injuries and chemical markers)
position of hyoid can suggest language/speech capabilities.

DNA Evidence

Some of the things we can determine from DNA:NOTE:  We are unable at this time to use DNA evidence from earlier hominins like the Australopithecines.  DNA evidence is currently possible from many recent Homo species.  Stay tuned.Location, location, location. (Example: As hominins move from place to place, their DNA alters, often just slightly, but enough to be associated with a specific region. As one group from one area contacts another group from a different ares, markers indicating their location become visible in the genomes of successive generations.)
Interbreeding. (Example: All non-Africans possess anywhere from 1 to 4 percent Neanderthal DNA.)
Approximate age of individual (and lifespan) As people age, they build up the same set of specific DNA changes at the same times. So, 20-year-olds might get a certain change, 30-year-olds might have a different one and so on. Scientists can then look and see what changes you have. Oh, he has a set typical of a 53-year-old and she has a set typical of a 29-year-old. And so far, it has really worked!
General health including presence of immunity genes (Toll-like receptor [TLR] gene clusters) passed on during interbreeding with Neanderthals and Denisovans.
Sight, hearing, intelligence, speech--there are genes for all of those.

Sahelanthropus

Ardipithecus

Paranthropus boisei  (c) JOHN BAVARO FINE ART/SCIENCE PHOTO LIBRARY

Homo erectus

The most successful human species so far: Homo erectus. 
Fossil and archeological finds show that erectus appeared about 2 million years ago and survived until approximately 100,000 years ago. 
Homo erectus moved out of Africa about 1.8 million years ago and spread through much of Asia and Europe.
OVERVIEW: https://humanorigins.si.edu/evidence/human-fossils/species/homo-erectus
OVERVIEW: https://www.nhm.ac.uk/discover/homo-erectus-our-ancient-ancestor.html
OVERVIEW: https://www.nature.com/scitable/knowledge/library/homo-erectus-a-bigger-smarter-97879043/
ARTICLES ABOUT: https://theconversation.com/us/topics/homo-erectus-9204

Near Extinction

During our migrations, various Homo species nearly went extinct THREE times.
            Around 1.2 million years ago, there may have been as few as 15,000 Homo hominins.  Those in Africa seemed to survive.
            About 150,000 years ago, a huge shift in climate (another Ice Age in the Northern Hemisphere) reduced Homo sapiens numbers to a few thousand, the largest group being in South Africa (archeological evidence, including shell fish and fire remains).
            About 70,000 years ago the Mt. Toba explosion in Sumatra sent the planet into a decades-long deep freeze--which again diminished numbers.
OVERVIEW: https://io9.gizmodo.com/close-calls-three-times-when-the-human-race-barely-esc-1730998797
MOUNT TOBA: https://www.npr.org/sections/krulwich/2012/10/22/163397584/how-human-beings-almost-vanished-from-earth-in-70-000-b-c
EARLY VICTIMS OF 6th EXTINCTION: https://theconversation.com/were-other-humans-the-first-victims-of-the-sixth-mass-extinction-126638

Homo Neanderthalensis

Six Important areas of Research1. Sophisticated Tool-making            The Levallois technique is a name given by archaeologists to a distinctive type of stone knapping developed by precursors to modern humans during the Paleolithic period.  It is named after nineteenth century finds of flint tools in the Levallois-Perret suburb of Paris, France. The technique was more sophisticated than earlier methods of lithic reduction, involving the striking of flakes from a prepared core. A striking platform is formed at one end and then the core's edges are trimmed by flaking off pieces around the outline of the intended flake. This creates a domed shape on the side of the core, known as a tortoise core as the various scars and rounded form are reminiscent of a tortoise's shell. When the striking platform is finally hit, a flake separates from the core with a distinctive plano-convex profile and with all of its edges sharpened by the earlier trimming work. This method provides much greater control over the size and shape of the final flake which would then be employed as a scraper or knife although the technique could also be adapted to produce projectile points known as Levallois points.           Morphometrics (from Greek "morphé", meaning 'shape' or 'form', and "metría”, meaning 'measurement') or morphometry refers to the quantitative analysis of form, a concept that encompasses size and shape.
2.  Did Neanderthals invent the world's first industrial process? (adapted from PBS’s NOVA website)            At some archeological sites, the Neanderthals subjected sticky substances to an elaborate process. Birch bark contains a tacky resin known as pitch that is impossible to extract simply by tapping into the tree, as with pinesap or maple syrup. Instead, the pitch must be separated from the bark by a process known as dry distillation. Chemists have discovered that distilling pitch from birch bark requires an oxygen-free environment and sustained temperatures of over 650° F. How could Neanderthals, with their Stone Age technology, have produced such conditions? If they really did master this complex process, it is hard to resist the conclusion that they must have had language and a sophisticated ability to think and plan ahead.            Evidence indicates that they successfully developed such a technique. The first discovery was made in 1963 at Kínigsaue, in then-East Germany. This was the site of an ancient lakeside hunting camp, from which Neanderthals had hunted now extinct Ice Age creatures such as mammoth and woolly rhino as well as red deer, horses, and reindeer. Two small, hardened lumps of black material were found during the dig, one bearing a fingerprint and the other the impression of a wooden haft or handle.In 2001, the lumps were dated to at least 40,000 years ago and were shown to have the chemical signature of birch bark pitch produced by the dry distillation process. Much older evidence was found at the Campitello quarry in central Italy. Here, the remains of an extinct elephant lay close to two large lumps of black pitch, which covered the end of two stone flakes crafted in a typical Neanderthal style.                       
            The Campitello find dates back over 200,000 years, a remarkably early origin for this complex process. A third Neanderthal site at Inden-Altdorf, overlooking the Inde River in Germany and dating to around 128,000 to 115,000 years ago, features more than 80 stone tools flecked with black material, but the chemical analysis indicating that this was distilled pitch requires further confirmation.But the archaeologists at Inden-Altdorf found an important clue: upon analyzing the pitch smeared on Neanderthal tools at the site, they detected traces of potassium, sulfur, and calcium, evidence that the material had been directly exposed to fire and ash during its manufacture. After some practical experiments, the team proposed that the Neanderthals had invented the following procedure: first, wrap a long strip of birch bark around a small pebble so that it forms a cigar-shaped roll. Next, dig a narrow pit, then set light to one end of the roll and place the burning end at the bottom of the pit. In the confined space at the bottom of the pit, the smoldering bark quickly uses up oxygen and causes the pitch to "sweat," or condense, out of the roll of bark onto the surface of the pebble. While still hot, the pitch is a sticky liquid that can be used immediately as glue.            Simple though it sounds in theory, the technique is highly challenging in practice. Procuring pitch today with Stone Age methods obviously calls for careful attention and considerable skill and judgment. Too low a temperature, and the bark fails to produce any pitch; too high, and the bark becomes hard and brittle; with too much oxygen, the bark burns up. As the experimental tests have shown, the temperature of the fire must be constantly monitored in varying wind conditions, the birch bark must be buried correctly with oxygen excluded and removed from the fire at the right time. Archaeologist Wil Roebroeks, who witnessed Palmer's NOVA experiment, comments that its failure underscores the complexity of the process, which "goes to show that they [the Neanderthals] were very capable pyrotechnologists. We're still learning how they did it a quarter of a million years ago."            Roebroeks adds that the significance of the Neanderthal pitches should not be overblown. "After all, they were produced by hunter-gatherers who survived in western Eurasia for hundreds of thousands of years in a wide variety of environments, successfully exploiting a wide range of mammals and other resources...That they discovered a trick or two which we are unable to reproduce nowadays should not come as a surprise—unless of course one assumes that they were 'complete idiots,' lacking the flexibility and learning capacities of other primates."            While Roebroeks warns about making too much of the glue finds, for other archaeologists, the mere fact that Neanderthals could make multi-part tools and weapons argues that they were capable of planning in depth, coordinating several tasks at once, and conceptualizing past and future. No single category of evidence can decide the case for the status of the Neanderthal mind, but the intriguing story of birch bark pitch joins a growing list of discoveries that indicate we may have underestimated the closeness of our bond with our long-vanished relatives from the Ice Age.
3. FOSSILS, DNA, AND LANGUAGE           A. FOSSIL EVIDENCE:                        a. Broca's area (or the Broca area) is a region in the frontal lobe of the dominant hemisphere (usually the left) of the hominin brain with functions linked to speech production.                        b. An endocast is the internal cast of a hollow object, often specifically used for endocasts of the cranial vault. They compliment the use of MRI’s and CAT scans to determine the shape and function of the brain within a skull.          B. GENETIC EVIDENCE:                    a. FOXP2 (Forkhead box protein P2) is a protein that, in humans, is encoded by the FOXP2 gene and is required for proper development of speech and language.                    b. Chromosomes are thread-like structures located inside the nucleus of animal and plant cells. Each chromosome is made of protein and a single molecule of deoxyribonucleic acid (DNA). Passed from parents to offspring, DNA contains the specific instructions that make each type of living creature unique.  Segments of DNA that pass on these instructions are called genes.FACT:  Genes are segments of DNA. The twisted double backbone of the DNA “ladder is connected with four nitrogen-bas molecules that form rungs of the ladder.  Those four molecules are ALWAYSconnected C to G and A to T.FACT:  DNA, or deoxyribonucleic acid, is a very long, thin molecule that is in the nucleus of most of our body's cells. It is constructed like a ladder (also called a double helix). Each rung on the ladder consists of two smaller molecules and all the rungs are spaced apart equally. Although each rung has only two molecules, there are only four different kinds of molecules used in the rungs, so each rung has two of four different kinds of molecules. There are approximately 3,000,000,000 rungs on the DNA ladder.            Each one of the rungs on the DNA ladder is like a letter on the page of a book - it means something in combination with the other rungs. Taken together the rungs are a language and they describe various things, one of which is the chemical formulas for approximately 90,000 proteins and enzymes that are essential to our body:            "The human genome contains approximately 3 billion of these base pairs, which reside in the 23 pairs of chromosomes within the nucleus of all our cells. Each chromosome contains hundreds to thousands of genes, which carry the instructions for making proteins. Each of the estimated 30,000 genes in the human genome makes an average of three proteins."  The Human Genome Project Completion: Frequently Asked Questions (National Human Genome Research Institute, 2010): HTTPS://WWW.GENOME.GOV/11006943            Imagine that 3 billion Aces, 3 billion Kings, 3 billion Queens and 3 billion Jacks are all arranged in thousands of different groups. If these cards were arranged in groups of four in one long line that is four cards thick and 3 billion cards long, the line of cards would circle the world approximately 6 times.            c. Hybridization:  When our Homo sapiens ancestors first migrated out of Africa around 50,000 years ago, they were not alone. At that time, at least two other species of hominin cousins walked the Eurasian landmass—Neanderthals and Denisovans. As our modern human ancestors migrated through Eurasia, they encountered the Neanderthals and interbred. Because of this, a small amount of Neanderthal DNA was introduced into the modern human gene pool.  Everyone living outside of Africa today has a small amount of Neanderthal in them, carried as a living relic of these ancient encounters. A team of scientists comparing the full genomes of the two species concluded that most Europeans and Asians have between 1 to 4 percent Neanderthal DNA. Indigenous sub-Saharan Africans have no Neanderthal DNA because their ancestors did not migrate through Eurasia.
4.  ART AND RITUAL            Once upon a time, in the dim recesses of a cave in what is now northern Spain, an artist carefully applied red paint to the cave wall to create a geometric design—a ladder-shaped symbol composed of vertical and horizontal lines. In another cave hundreds of kilometers to the southwest another artist pressed a hand to the wall and blew red paint around the fingers to create a stenciled handprint, working by the flickering firelight of a torch or oil lamp in the otherwise pitch darkness. In a third cave, located in the far south, curtainlike calcite formations were decorated in shades of scarlet.               Although nothing of the artists themselves remains to establish their identity, archaeologists have long assumed cave painting was the sole purview of Homo sapiens. Another group of large-brained humans, the Neandertals, lived in the right time and place to be the creators of some of the cave art in Europe. But only H. sapiens had the cognitive sophistication needed to develop symbolic behavior, including art. Or so many experts thought.            Now dates obtained for the images in these three Spanish caves could put that enduring notion to rest. In a paper published in 2018 in Science, researchers report some of the images are far older than the earliest known fossils of H. sapiens in Europe, implying they must have instead been created by Neandertals. The findings open a new window into the minds of these oft-maligned cousins of ours. They also raise key questions about the origin of symbolic thought, and what, exactly, distinguishes H. sapiens from other members of the human family.    (c) Scientific American
            Current evidence also suggests that Neanderthals buried their dead with mortuary rituals, including the streing of flowers. 
OVERVIEW: https://arstechnica.com/science/2018/02/neanderthals-were-artists-and-thought-symbolically-new-studies-argue/
OVERVIEW: https://www.scientificamerican.com/article/ancient-cave-paintings-clinch-the-case-for-neandertal-symbolism1/BURIALS: https://www.newscientist.com/article/2233918-70000-year-old-remains-suggest-neanderthals-buried-their-dead/
BURIALS:  https://www.nbcnews.com/science/science-news/did-neanderthals-bury-their-dead-flowers-iraq-cave-yields-new-n1138601

5. EXTINCTION THROUGH HYBRIDIZATION            Hypotheses on the fate of the Neanderthals include a failure or inability to adapt to climate change, competitive exclusion, or extinction by encroaching anatomically modern humans, who arrived in Europe long after Neanderthals had settled there. Neanderthal hybridization with early modern human populations is also considered a viable hypothesis. Some interbreeding took place in western Asia about 50,000 to 60,000 years ago, as evidenced by 1 to 4 percent of the material of genomes carried by non-African people living today.            Regionally developed ecotypes (such as European Homo neanderthalensis) can be threatened with extinction when new alleles or genes (such as those of Homo sapiens) are introduced to alter that ecotype.  This is sometimes called genetic mixing.  An allele is a variant form of a gene.  Some genes have a variety of different forms, which are located at the genetic locus on a chromosome.  Humans are called diploid organisms because they have two alleles at each genetic locus, with one allele inherited from each parent.  A locus (plural loci), in genetics, is the specific location or position of a gene on a chromosome.  Each chromosome carries many genes; humans’ estimated coding genes are 20,000—25,000, on the 23 different chromosome pairs.            Hybridization and introgression of new genetic material can lead to the replacement of local genotypes if the hybrids are more fit and have breeding advantages over the indigenous ecotype or species. These hybridization events can result from the introduction of non native genotypes by humans or through habitat modification, bringing previously isolated species into contact. Genetic mixing can be especially detrimental for rare species in isolated habitats, ultimately affecting the population to such a degree that none of the originally genetically distinct population remains.
6. WHAT DID WE GET FROM THE NEANDERTHALS?             Scientists have discovered a novel receptor, which allows the immune system of modern humans to recognize dangerous invaders, and subsequently elicits an immune response. The blueprint for this advantageous structure was in addition identified in the genome of Neanderthals, hinting at its origin. The presence of this receptor in Europeans but its absence in early humans suggests that it was inherited from Neanderthals.            Neanderthals probably lived many hundreds of thousands of years in Europe during which time they developed the HLA receptor that provided them with immunity against many pathogens. This means that different to our ancestors from Africa, the Neanderthals which were resident in Europe, carried this receptor on their immune cells. That was a “distinct evolutionary advantage,” says an immunobiologist from the University of Bonn, who presumes that we modern humans in Europe owe this advantageous receptor to the Neanderthals.            Neanderthals and other extinct humans like the Denisovans might have endowed some of us with the robust immune systems we enjoy today, scientists now find.  These genetic gifts might have helped our species as we expanded out of Africa, investigators added.  Although we modern humans are the only surviving members of our lineage, others once roamed the Earth, including familiar Neanderthals and the newfound Denisovans, who lived in what is now Siberia. Genetic analysis of fossils of these extinct lineages has revealed they once interbred with our ancestors, with recent estimates suggesting that Neanderthal DNA made up 1 percent to 4 percent of modern Eurasian genomes and Denisovan DNA made up 4 percent to 6 percent of modern Melanesian genomes.            (Bottom line:  When we examine ancient DNA from Africa, samples LACK the HLA receptors; when we examine samples from Europe and Asia, they contain the HLA receptor—probably inherited from Neanderthals and Denisovans (who also interbred with each other most likely.)

HOMINID versus HOMININ:  http://www.smithsonianmag.com/science-nature/whats-in-a-name-hominid-versus-hominin-216054/?no-istTHE HOMININ FAMILY TREE: http://humanorigins.si.edu/evidence/human-family-treeLEVALLOIS TOOL-MAKING:  http://archaeology.about.com/od/lterms/g/levallois.htmNEANDERTHALS AND THE USE OF “INDUSTRIAL GLUE”:  http://www.pbs.org/wgbh/nova/evolution/defy-stereotypes.htmlFOXP2 GENE AND LANGUAGE: https://en.wikipedia.org/wiki/FOXP2WHAT IS A CHROMOSOME AND WHAT DOES IT DO? https://www.genome.gov/26524120NEANDERTHAL—SAPIENS HYBRID:    http://www.the-scientist.com/?articles.view/articleNo/43354/title/Neanderthal-Human-Hybrid-Unearthed/NEANDERTHAL—SAPIENS HYBRID:  http://news.discovery.com/human/evolution/neanderthal-skeleton-provides-evidence-of-interbreeding-with-humans-130327.htmNEANDERTHAL—SAPIENS HYBRID: http://www.bbc.com/earth/story/20151013-how-interbreeding-shaped-usNEANDERTHALS KEEP HOMO SAPIENS OUT OF EUROPE: http://www.theguardian.com/science/2015/oct/17/neanderthals-kept-early-homo-sapiens-out-of-europeNEANDERTHAL EXTINCTION THROUGH HYBRIDIZATION: http://news.nationalgeographic.com/news/2013/12/131216-la-chapelle-neanderthal-burials-graves/NEANDERTHAL EXTINCTION:  https://en.wikipedia.org/wiki/Neanderthal_extinction

Morocco Dig Site

Early Homo sapiens

New evidence shows that Homo sapiens existed much earlier than previously thought:300,000 years ago rather than 200,000 years ago. 
They lived throughout Africa. 
Homo sapiens moved out of Africa 100 to 120 thousand years ago--at least 50 thousand years earlier than originally thought. And they moved out in several waves. 

HOMO SAPIENS IN MOROCCO:
SCIENCE MAGAZINE: http://www.sciencemag.org/news/2017/06/world-s-oldest-homo-sapiens-fossils-found-morocco
NY TIMES: https://www.nytimes.com/2017/06/07/science/human-fossils-morocco.html
CNN: http://www.cnn.com/2017/10/25/africa/inside-africa-morocco-homo-sapiens-fossils/index.html

Who is our common ancestor?

A current question:  Did Homo sapiens evolve from Homo erectus or from Homo heidelbergensis?

            A few researchers have generally opposed the view that H. erectus was the direct ancestor of later species, including Homo sapiens. Louis Leakey argued energetically that H. erectus populations, particularly in Africa, overlap in time with more advanced Homo sapiens and therefore cannot be ancestral to the latter. Some support for Leakey’s point of view has come from analysis of anatomic characteristics exhibited by the fossils. By emphasizing a distinction between “primitive” and “derived” traits in the reconstruction of relationships between species, several paleontologists have attempted to show that H. erectus does not make a suitable morphological ancestor for Homo sapiens. Because the braincase is long, low, and thick-walled and presents a strong browridge, they claim that H. erectus shows derived (or specialized) characteristics not shared with more modern humans. At the same time, it is noted, Homo sapiens does share some features, including a rounded, lightly built cranium, with earlier hominins such as H. habilis. For these reasons, some paleontologists (including Leakey) consider the more slender, or “gracile,” H. habilis and H. rudolfensis to be more closely related to Homo sapiens than is H. erectus. These findings are not widely accepted, however. Instead, studies of size in human evolution indicate that representatives of Homo can be grouped into a reasonable ancestor-to-descendant sequence showing increases in body size. Despite having a heavier, more flattened braincase, H. erectus, most particularly the African representatives of the species sometimes called H. ergaster, is not out of place in this sequence.            If this much is agreed, there is still uncertainty as to how and where H. erectus eventually gave rise to Homo sapiens. This is a major question in the study of human evolution and one that resists resolution even when hominin fossils from throughout the Old World are surveyed in detail. Several general hypotheses have been advanced, but there is still no firm consensus regarding models of gradual change as opposed to scenarios of rapid evolution in which change in one region is followed by migration of the new populations into other areas.  (c) Britannica.com; retrieved 22 April 2021

Fossils and DNA confirm humans are one of more than 200 species belonging to the order of Primates. Within that larger group, humans are nested within the great ape family. Although we did not evolve from any of the apes living today, we share characteristics with chimpanzees, gorillas, and orangutans (the great apes), as well as other apes. We most likely evolved from Homo heidelbergensis, the common ancestor we share with Neanderthals, who are our closest extinct relatives.  (c) https://humanorigins.si.edu/evidence/human-fossils/species/homo-sapiens

ARTICLE: https://www.newscientist.com/article/2239329-we-may-now-know-what-our-common-ancestor-with-neanderthals-looked-like/HOMO ERECTUS: https://www.nhm.ac.uk/discover/homo-erectus-our-ancient-ancestor.html

https://www.nhm.ac.uk/discover/the-origin-of-our-species.html

Human Origins

Early Primates

Old World and New World Monkeys

Old World Monkeys and the Great Apes

Fossil Evidence

Archeological Evidence

DNA Evidence

Hominin Changes

The Earliest Hominins: Sahelanthropus, Orrorin, and Ardipithecus

Australopithecines

Paranthropus

Homo erectus

Near Extinction

Homo Neanderthalensis

Hybridization & Interbreeding

Early Homo sapiens

Who is our common ancestor?