Evolution and CultureA night of discussion and discovery at Ben’s Barn

Evolution and Our Place in the World

A night of discussion and discovery at Ben’s Barn

Philosophy Science Religion

Who am I? Where do we come from?

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Epistemology and semantics

• Epistemology: 1- (episteme: knowledge; epistanai: to understand, believe) the study or theory of the nature, sources, and limits of knowledge.

• Semantics: 1- the branch of linguistics concerned with the nature, the structure, and the meanings of speech forms, or with contextual meaning, as opposed to ; 2 - loosely, a deliberate distortion or twisting of meaning, as in some types of advertisements and propaganda.

The language of science• Science is not about finding the truth, but

about reducing uncertainty.• Proving something does not make it true.

Proving something is an exercise in logic.• Science collects empirical evidence through

experimentation (uniformitarianism).• What is a fact? An undisputed piece of

information. A scientific observation. Something that can be repeatedly shown to be an aspect of reality. Facts are testable.

Laws, hypotheses, and theories

• Scientific law: a generalized description, usually expressed in mathematical terms, that describes the empirical behavior of matter.

• Scientific laws describe things. They do not explain them. (Newton vs. Einstein.)

• Hypothesis: a proposal of a possible explanation for the observed “behavior” of the natural world. Hypotheses are tentative.

• A hypothesis is an educated guess about the best way to explain a phenomenon and it can be tested by experiment.

Theories• Theories are the pinnacle of scientific

endeavor. They are the most powerful scientific explanations of why the physical world behaves the way it does. They are based on and explain all the facts and observations that have been gathered by scientists around the world up until today. Some theories explain millions of facts.

• Scientific theories are powerful predictive and explanatory tools in science.

Evolution is a fact and a theory

• Antibiotic arms race.• Macintosh apples in upstate NY.• The predicted moth.• Atavisms.• The evolution of the eye.• The predicted moth.

Angraecum sesquipedale

Milestones in human evolution

Links

• http://humanorigins.si.edu/evidence/human-fossils/species/human-family-tree

• http://humanorigins.si.edu/evidence/human-fossils/species/human-family-tree

Our closest relatives• While the genetic difference between

individual humans today is miniscule – about 0.1%, on average – study of the same aspects of the chimpanzee genome indicates a difference of about 1.2%. The bonobo (Pan paniscus), which is the close cousin of chimpanzees (Pan troglodytes), differs from humans to the same degree. The DNA difference with gorillas, another of the African apes, is about 1.6%.

More distant relatives• Most importantly, chimpanzees,

bonobos, and humans ALL show this same amount of difference from gorillas. A difference of 3.1% distinguishes us and the African apes from the Asian great ape, the orangutan. How do the monkeys stack up? All of the great apes and humans differ from rhesus monkeys, for example, by about 7% in their DNA.

How relatedness is measured

• Geneticists have come up with a variety of ways of calculating the percentages, which give different impressions about how similar chimpanzees and humans are. The 1.2% chimp-human distinction, for example, involves a measurement of only substitutions in the base building blocks of those genes that chimpanzees and humans share. A comparison of the entire genome, however, indicates that segments of DNA have also been deleted, duplicated over and over, or inserted from one part of the genome into another. When these differences are counted, there is an additional 4 to 5% distinction between the human and chimpanzee genomes.

The kinship is very close• No matter how the calculation is done, the big

point still holds: humans, chimpanzees, and bonobos are more closely related to one another than either is to gorillas or any other primate. From the perspective of this powerful test of biological kinship, humans are not only related to the great apes – we are VERY CLOSELY related. The DNA evidence leaves us with a keen appreciation of our place in the tree of all life. The human evolutionary tree is embedded within the great apes and we are just one species of mammal. Does this have implications regarding how we should behave towards other living things?

Predictive power of science• The strong similarities between humans and the

African great apes led Darwin in 1871 to predict that Africa was the likely place where the human lineage branched off from other animals – that is, the place where the common ancestor of chimpanzees, humans, and gorillas once lived. DNA evidence shows an amazing confirmation of this daring prediction. The African great apes, including humans, have a closer kinship bond with one another than the African apes have with orangutans or other primates. Hardly ever has a scientific prediction so bold, so ‘out there’ for its time, been upheld as the one made in 1871 – that human evolution began in Africa.

African origins• The DNA evidence informs this

conclusion, and the fossils do, too. Even though Europe and Asia were scoured for early human fossils long before Africa was even thought of, ongoing fossil discoveries confirm that the first 4 million years or so of human evolutionary history took place exclusively on the African continent.

Numeracy and why it’s critical to understanding evolution.

Natural Selection: How it works

Sexual Selection: How it works

Sexual SelectionWhy size matters.

Cheap Expensive

Why getting old sucks.

DNA 101

What are Genes, Chromosomes & Phenotypes?

Our 23 sets of chromosomes

Homo sapiens taxonomy• The cladistic line of descent (taxonomic rank) of homo sapiens sapiens

(modern humans) is as follows:• domain: eukaryotes (2.100.000.000 years ago)

kingdom: animalia (590.000.000 years ago)phylum: chordata (530.000.000 years ago)subphylum: vertebrata (505.000.000 years ago)class: mammalia (220.000.000 years ago)infraclass: eutheria (125.000.000 years ago)superorder: euarchontoglires (supraprimates) (100.000.000 y. ago)order: primates (75.000.000 years ago)suborder: haplorrhini (tarsiers, monkeys, apes, "dry-nosed" primates) (40.000.000 years ago)infraorder: simiiformes (simians, "higher" primates)parvorder: catarrhini ("narrow nosed" primates) (30.000.000 years ago)superfamily: hominoidea (25.000.000 years ago)family: hominidae (great apes) (15.000.000 years ago)subfamily: homininae (4.500.000 years ago)tribe: homininisubtribe: hominina (3.000.000 years ago)genus: homo (2.500.000 years ago)species: homo sapiens (500.000 years ago)sub-species: homo sapiens sapiens (200.000 years ago)

Vestigial Organs as physical evidence of evolution.

Vestigial Organs as physical evidence of evolution.

Pseudogenes (Switched off Genes) and how they’re proof of the

evolutionary process.

Chicken Embryo

Fossils and what they tell us about Evolution

Genographic Project

“The Population Bottleneck 60,000 years ago”

Where did Ben come from?

Ben R.

Where did Ben come from?

We started here.

Where did you go?

Race?

Human Nature and how we are different than other species.

• Preferring relatives over non-relatives

• Fashion/body adornment

• Language• Music• Dance• Gossip• Self Awareness

I am here now. The Emergence of Self Awareness

Are we still evolving?Thank you.