Lecture Part Of 5, 6, And 7

Question 1

A tale of three lice

Answer 1

Lice are highly specialized blood sucking parasites that live on a single organism
Each of our ape relatives host 1 species of lice, we house 3

Question 2

New niche hypothesis about lice

Answer 2

Human pubic and head lice lineages diverged because hominins lost their body hair and developed two hair hypothesis

Human head and pubic lice did not diverge on a hominin

Question 3

Tree thinking with lice divergence

Answer 3

Human pubic lice belong to the same genus as gorilla lice
Hominins might have picked it up by killing/eating gorillas or sleeping in abandoned nests.

Question 4

Human body lice hypothesis

Answer 4

Human body lice live on clothing and move onto skin up to 5 times a day to feed

Question 5

What created the conditions for the evolution of aging? and about when did it occur?

Answer 5

asymmetric division of bacterial cells
more than 3 billion years ago

Question 6

What was the consequence of stem cells evolving and when did they evolve?

Answer 6

They are pre-adapted to become cancer cells and 1-2 billion years ago

Question 7

what started the evolution of the vertebrate adaptive immune system and when did it occur?

Answer 7

retrovirus insertion into proto-immunoglobulin gene about 500 million years ago

Question 8

What evolved about 15 million years ago in the shared ancestor of orangutans, gorillas, chimpanzees, and humans?

Answer 8

highly invasive placentas

Question 9

What is asymmetric division?

Answer 9

in cell division, one cell gets the newer parts and the other cell, the older parts
the cell lineage with the older parts will die out sooner and the cell lineage with the newer parts will persist
selection invests less resources in cells that are weaker

Question 10

The consequence of cell division was perfectly symmetrical

Answer 10

it would be impossible for selection to distinguish between mother and daughter cells: both would be equally intact or equally damaged; the reproductive payoff from improving the maintenance of both would be equal

Question 11

What will evolve as a cost of reproductive performance?

Answer 11

aging

Question 12

asymmetric cell division e. coli example

Answer 12

• grows in the form of a rod, which reproduces by dividing in the middle
• old poles can exist for many divisions, and if cells are followed over time, an age in divisions can be assigned to each pole
  -there is evidence of aging in the old pole

Question 13

Aging in a single-celled organism that is apparently meticulously symmetric others may indicate that it is

Answer 13

1) not cost-effective to produce an immortal life form
2) impossible to achieve perfect molecular maintenance through natural selection

Question 14

why are stem cells pre-adapted to a cancerous lifestyle and where are they most prevelant?

Answer 14

they have the potential to differentiate and move
in bone marrow, lungs, intestine, and skin (malignant cancer is frequent in these tissues)

Question 15

how was the adaptive immune system acquired?

Answer 15

evolved in the ancestor of jawed fishes when an immunoglobulin-like gene was invaded by a transposable genetic element (jumping genes)
the acquisition of transposon machinery allowed lymphocytes to generate diverse antigen receptors via somatic recombination to recognize and repel pathogens

Question 16

which species did highly invasive placentas evolve?

Answer 16

the great apes

Question 17

what are the advantages and disadvantages of invasive placentas?

Answer 17

Adv: fetal stem cells invades the endometrium and inserts itself into maternal spiral artery; this allows the fetus to control blood pressure and sugar
Dis: increased risk of metastatic cancer

Question 18

when did gorilla lineage split from the lineage that would become humans and chimps?

Answer 18

about 6 mya

Question 19

when did the human and chimp lineages split?

Answer 19

about 5 mya

Question 20

due to how large our genome, what contradictory statements are true

Answer 20

we share 99.9% of our genome but 3.3 million positions are different
first suggests how conservative inheritance is and second points to its flexibility

Question 21

which is better predictor of biogenetics, race or ethnicity?

Answer 21

ethnicity

Question 22

patients vary genetically in their ability to ___ _____ __________ in part because of their evolutionary history

Answer 22

resist infectious diseases

Question 23

genetic variation in disease resistance examples:

Answer 23

heritability- children are at a greater risk if their parents had it
variability- for several diseases, many get infected but few get sick
local adaptation- ppl living in areas where disease is endemic are often more resist than those from a region where the disease does not exist

Question 24

diseases that have been interacting with humans for a long time…

Answer 24

played a major role in shaping our genome

Question 25

the ABO blood group poly morphism is

Answer 25

one of the genetic systems implicated in disease resistance
ex. type B is more resistant to cholera and the Norwalk Virus (diarrhea)

Question 26

___ ___ was most strongly correlated with levels of variation in susceptibility

Answer 26

vaccine efficacy

Question 27

diseases that ___ ____ adaptive immune responses, i.e. short infectious periods, result in low levels of variation in their host

Answer 27

evoke effective

Question 28

diseases that ____ the adaptive immune system, i.e. long infectious periods, are associated with high levels of variation in susceptibility

Answer 28

circumvent

Question 29

what are GWAS

Answer 29

genome-wide association studies
used to find genetic effects for common, chronic, and late onset diseases where relative risks are lower and polygenic effects are common