Lesson 1: The Human Family
1.1 Introduction
1.2 1st segment
About 13 billion years ago, matter, energy, time, and space came into being in the Big Bang.
The study of matter, energy, time and space is PHYSICS.
Matter, energy, time and space started forming complex structures 300k years later (atoms),
then even more complex structures. The study of atoms, molecules, and their interactions is
CHEMISTRY.
Molecules made even larger, more complex structures called organisms (4billion years ago)
Study of living creatures is BIOLOGY.
70k years ago- organisms called homo sapiens started forming structures called cultures.
Study of cultures/the interaction of cultures is HISTORY.
3 important things in history
Cognitive revolution- 70k years ago evolved great thinking abilities.
Agricultural revolution- 12k years ago- domestication of animals and plants. Establishment of
permanent settlements, more complex societies.
Scientific revolution- 500 years ago- understanding the rules governing the natural world and
gained more power.
First humans 2.5 million years ago in E. Africa, but did not become modern until 70k years
ago
Just another animal. No more impact on the world than any other animal.
A species mates and produces fertile offspring together
Horses and donkeys mate, but mules are sterile- two different species.
Different breeds of dogs do have fertile offspring- same species
A group of species from same ancestor is Genus (pl. genera)
Homo sapience “men” “wise” (wise but not modest! Lol)
A group of genera is a family
all members of family trace back to one ancestor
homo sapiens part of great apes
6 million years ago- common ancestor between chimps and humans- a mother had two daughters.
One became the ancestor of humans, the other the ancestor of chimps (see reflection)
“humans” is genus homo
Other humans way back when tooAustralopithecus (“southern ape”) 6m y/a
2m y/a- left E. Africa and spread- each area met new conditions and evolved.
Europe/middle east- Homo neanderthalensis “man from the neander valley” or Neanderthalsadapted to colder environments- bigger, muscular, insulation fat, bigger brains.
Java in Indonesia- homo soloensis “man from the solo valley”- adapted to tropics.
Flores in Indonesia- homo florensiensis “man from flores island”- dwarfs. Used to be connected to
mainland, but sea levels rose and was cut off. Not much to eat, so big people died first. Little people
survived, so it was a selected trait.
Tiny people hunting tiny elephants
Homo erectus- “upright man” in Asia. Tall. The most successful human species for years of survival.
1.5 million years ago until 50k years ago. (homo sapiens 300-200k years)
Denisova cave in Russia- finger bone DNA- a new species. Homo denisova “man from the denisova
cave”
e. Africahomo rudolfensis “man from near lake Rudolph”
homo ergaster “working men” tools found nearby
homo sapiens
not a straight line of descent. There were more than one type of humans at a time until more
recently (10k y/a)
100k y/a at least 6 different species of humans
What is surprising is that now there is only one species. Homo sapiens had a hand in the destruction of
our brothers and sisters (see reflection)
Reflection- looking at the Bible as metaphor, could we not say that God’s creation of adam
was actually the cognitive revolution, or the spark that separated that one ape mother with
one homo child and one chimp child? When Cain killed Abel, could that not be the
representation of homo sapiens killing homo neaderthalesis or erectus? Perhaps there is
much to be understood if one does not take religion as outright, literal fact, but as metaphor
from our earliest histories.
1.3 2nd segment
Defining characteristics of humans
Extraordinarily large brains.
Big brain is good but also a problem. Have to carry it, have to protect it, have to fuel it (2-3% of
body weight, 25% of energy at rest- apes only 8% energy),
Had to spend more time looking for food
Less muscular to pay for brain’s energy consumption
Why the brain got so big is one of the biggest mysteries- happened for long time with no real
observable bonuses
Walk upright on two legs
Advantages- better for sight, see farther. Hands are freed for use/tools, signaling, etc. more
nerves/muscles evolved in hands allowing for delicate operation
Tools produced 2.5 m years ago
Disadvantages- skeleton is not optimized- spine stress. Hips have to be relatively narrow and close,
therefore birth canal is narrow while heads were getting bigger. More death during childbirth (both
child and mother). Babies started being birthed earlier when head was still small and squishy.
Shorter gestation period than any other. Babies helpless for years. Animals can walk in hours.
Human children need care and attention because they are helpless for so long. Thus a single parent
cannot care sufficiently (takes a village to raise a child), therefore social ties built stronger. People live
in groups to care for children.
Humans can be educated and socialized far more than animals.
Most humans were not good hunters- had to forage and eat small animals. Stone tools first
used to crack open dead bones for marrow, not to hunt. Lions kill a giraffe and eat most
meat. Hyenas/wolves eat the rest. All that’s left for the humans is marrow.
Humans in the middle of the food chain. Hunted and only hunt small animals.
In last 100k years we jumped to top of food chain with homo sapiens.
Consequences- not used to being top predators. Wars and environmental disasters result from
this jump. We don’t know what to do with power.
1.4 3rd segment
Domestication of fire
~300k y/a using fire on daily basis
Advantages- light in the dark, warmth in cold, weapon against dangerous animals, changing
the environment- fire to burn forests to find food. Best thing- enabled to cook
Cooking- more foods available to eat. Can’t digest wheat, rice, potatoes until cooked. Kills germs and
parasites in food, particularly meat. Reduced time required to chew and time/energy for digestion. > smaller teeth, jaws, intestines
Smaller intestines mean less energy for digestion, more energy for brain. Even bigger brain.
Power of animal is linked to power of body. Can harness nature power (wind/water current).
Eagles can soar in wind currents. Still power is proportional to wingspan/muscle/teeth/whatever
With fire, human power is no longer linked to power of body
Humans still not the most important/powerful animal in world with fire
Not until homo sapiens.
1.5 4th segment
200-300k y/a
By 150k y/a, e. Africa had homo sapiens that looked like us. Some left and migrated all over
Eurasia. World was already populated by other humans
Interbreeding theory- sapiens bred with others. Sapiens and neaderthals in Europe and
middle east. In asia, homo erectus. This would mean we are not pure sapiens, except maybe
Africans
Replacement theory- incompatibility, revulsion, genocide. Different species have infertile
children. So they may have children, but not grandchildren. Other species were an
evolutionary dead end. If true, we are all pure sapiens
Important political implications.
Replacement theory- all have same dna, genetic baggage, etc. and differences b/w people are
negligible (or based on culture)
Interbreeding- may be actual differences in race going back 100k years. May have unique
genes and significant differences. Physical, mental, psychological qualities
Political dynamite!
Replacement had better evidence, but more importantly, more politically correct.
2010- neaderthal genome published. Found that 4% of the unique human genes in ME and
Europe are Neanderthal.
A few months later, 6% of Melanesians and aboriginal Australians are denisova genes.
May have intermingled, but did not merge. Maintained distinct groups.
If they didn’t merge, why did they vanish?
Could be because homo sapiens out-competed them. Sapiens were already more sophisticated
than Neanderthals, so they got fed and Neanderthals didn’t.
Could have been less peaceful- genocide and war when competing.
Homo sapiens has become accustomed to being the only humans -> epitome of creation, and
a gap b/w us and other animals
solensis 50k y/a extinct when sapiens got to java
denisova 40k y/a extinct
Neanderthals 30k y/a
Florensis 12k y/a