Exodus of Early Man Flashcards
organisms
example: elm grove in utah (pando)
- Is a sprout from another tree an organism? If you take it from another place to another would it still be another organism?
- It simply a definition
- Do trees know they are alive? Other organisms?
species
- no such thing, it is all made up
- Two groups of organisms that cannot interbreed
- Do bacteria have species? - - Do not have sex (infection)
- Do bacteria live forever? -
- Once they split from the mother, which of the two daughter cells is the mother?
ring species
- a situation in which two populations which do not interbreed are living in the same region and connected by a geographic ring of populations that can interbreed.
- example: the gull and san joaquin valley salamanders
List differences between archaic and modern man
- smaller brain size: 500,000 years ago brain size increased significantly
200,000 years ago it reached modern levels - behaviorally: culture developed
- anatomically: happened before anatomically modern humans; we cannot swallow and breathe at the same time
- racial variations: The racial variation of the genus homo developed only within the last 100,000 years
- capacity for highly developed language
Which hominid was the first to have bipedal locomotion?
Australopithecus
When and who developed Art?
- Cro magnum was the first to develop art and the distinction between other hominids
- Occurring 45,000 years ago
- The emergence of language, art, enhanced too making, science
- Are these traits due to mutated genes?
- Archaeologists believe that the appearance of art correlates with the development of complex language
When was fire introduced?
1.7 million years ago
When did the Hominids begin to use fashioned stone tools?
- Tool making advanced in stages corresponding to large scale changes in genetic makeup
- Homo habilis was the first to develop this around 2.5-1.7 million years ago
- Homo erectus and neanderthaals started to develop more advanced tools around .25 and .05 mya but stayed in this state for 200,000 years
- Cro magnum developed even more after them
Understand the role of SRGAP2 in Hominid evolution
- Has made higher culture possible
- Duplications in SRGAP2 may have played an important role in human evolution
- First time it duplicated was before “Lucy” (australopithecus) = 3.2 mill
- Second time was around homo habilis and erectus 2.4 mya; Stone tools developed
- Third time occurred around 1 mya with homo neanderthalensis and homo antecessor; Fire developed shortly after
What is “neoteny”?
- Observed with the SRGAP2 gene that was mutated 3 times
- Prolonging of the juvenile stage
- Retention of juvenile characteristics in the adults of species
Understand role of FOXP2 transcription factor in the evolution of modern Homo sapiens.
- Thought to give us language
- Is the difference between archaic and modern humans
- This gene and broca’s area is thought to attribute to handedness
- If you mutate it, the people who have it have trouble constructing sentences
CNTNAP2 gene has a role in what?
(autism, dyslexia, schizophrenia, Tourette syndrome and depression
what is the potential connection between FOXP2 and CNTNAP2?
- FOXP2 may contribute to its regulation based on a binding site located on the CNTNAP2 gene
- Has a binding site for FOXP2 in intron 1
which mutation is useful in establishing a molecular clock?
Synonymous is useful in establishing a molecular clock
where is positive selection pressure the strongest and what does it mean?
phylogenic tree - the higher the ratio the more positive selection pressure there is
homo erectus
archaic humans (asia)
homo Neanderthals
archaic humans (europe/middle east)
homo sapiens
- The earth was only populated by archaic humans until about 200,000 years ago
- Underwent a genetic bottle neck and went down to 10,000 mating pairs about 70,000-90,000 years ago - possibly drove the third exodus
synonymous mutation
- Second or bottom number in the ratio
- No evolutionary change
- No change in the amino acid residue encoded in the protein, neutral, molecular clock
- Mitochondrial D-loop region
nonsynonymous mutation
- First or top number in the ratio
- Change the amino acid
- Rate of nonsynonymous to synonymous mutations gives indication of selection pressure. High percentage of nonsynonymous indicates positive selection
molecular clock
- The number of synonymous mutations within a population gives a measure of the time elapsed
- How often mutations appears
- How one variation changes versus to another
- Mitochondrial
SRGAP2
- guides neurons where to go
- More and more elongated necks off of the dendrites
- Shortened when it was mutated and could not function correctly and binds to the wild type and causes that to malfunction as well
- The mutant form combines with the original form and becomes insoluble and precipitates out; interferes with the original function - slows down brain development
- Has been duplicated three times in the human line and not in other primates
what changes in primate evolution has SRGAP2 changed?
- An increase in the length of dendrite stems and an increase in the spines
- Believes to increase capacity for cognitive brain development
- Correlates with the beginning of neocortex expansion in the hominin line
- A slowing down of brain development
When did man become behaviorally modern?
Comparisons of non-synonymous and synonymous mutations in FOXP2 suggest that it occurred 400,000 - 600,000 years ago (before cro magnon split from neanderthals). Too early to account for the relatively recent development of art which appeared approximately 50,000 years ago
when was the first exodus?
- 600,000-700,000 years ago with homo heidelbergensis
- start of the archaic human
what happened after the split from homo heidelbergensis?
- migrated away from africa into colder regions and became cold adapted
- The species split from this include homo denisova and homo neanderthals
what was the second exodus?
- occurred around 120,000 years with homo sapiens
- went along Mediterranean but got rebuffed by the Neanderthals
what was the third exodus?
- occurred around 60-70,000 years ago again with homo sapiens
- Gone southern route into indonesia, india, australia, etc. and coming into neanderthals in europe
- became old adapted
