Week1-7 Flashcards
What are Darwins observations?
- Variation exists in all populations
- some variation is heritable
- any traits better suited to an environment will tend to increase in frequency, while other variants decrease
What is natural selection?
Individuals better suited to their environment are more likely to survive, and have offspring with a good chance of inheriting those traits
What is selective pressure?
-drives evolution and natural
selection in a certain direction
-can be high or low
- when a gene affects something very important for survival, selective pressure is high
Examples of selective pressure
Gulo- gene that allows the body to produce its own vitamin C
What is a species? And example
The offspring have to be fertile to
Interbreed
Ex: non fertile hybrids
A horse and donkey may produce a mule or a hinny but it is infertile.
What is a genotype? And example
Genetic makeup
Ex: Bb for eye colour
What is a phenotype? And example
Physical appearance
Ex: brown eyes
Example of dominance
Brown eyes, right handed, widows peak, detached earlobes.
Examples of ressesive
Blue eyes, left handed, attached earlobes
What is incomprehensible dominance?
Cross between organisms with 2 different phenotypes produce offspring with a 3rd phenotype.
Sex chromosomes?
Xx-female xy- male
What is recombination?
Joining of strands of DNA from different organisms.
Ensure children are not replicas of their parents
How is it determined if a mutation is advantageous?
If the mutation is useful and become positive. Makes it useful to survive in your environment.
What is meant by the tree of life?
- We’re all related.
- we all mutated from each other, all from a common ancestor
What does the LUCA stand for and how long ago did it live
Last- universal- common- ancestor
3.8 billion years old
What happens to a species when there is a change in the environment?
The traits will change, more mutation
Ex: 2 populations will become very different to survive in their environment, they adapt
What is the difference between Gradualism and Punctuated Equilibrium?
Gradualism-> they slowly get better
Punctuated-> changes in a relatively static way . huge changes, huge leaps forward, rest for long time.
How would you respond to someone who questions the validity of evolution because it’s “just a theory” ?
The theory brings all the facts together. Not just someone’s guess, it’s based on facts and research.
Why aren’t there a lot of fossils?
Erosion, storms, decompose, animals eat their carcasses
How are vestigial structures used to support evolution?
Appendix, wisdom teeth, tail. We need them at one point but our environment changed and we adapted
What is relative dating?
Comparing strata with one another to discover which one is older
What is absolute/ numerical dating?
More precise; establishes a range of dates
Why was the Hadrian era considered “hellish”? Was it possible for life to exist?
It was a giant fireball, has a lot of iron, no oxygen or bacteria so it was impossible for life to exist
When did the first mammals appear?
The mezazoic era
What was the “great dying”
Marine life dead from methane in water
Volcanic eruption
Extinction of insects
What was the key evolutionary trait of the Cenozoic?
Adaption
Can relative dating give us a date for a fossil?
No
Name one dating method that can be used in the study of human evolution
Absolute dating
What is biological evolution?
Descent with modification through genetic inheritance, relies on natural laws, evidence and is testable
What is creationism?
The present universal and all life forms came about as a result of the action of a divine creator (super natural)
Problems of biological evolution?
Discuss adaption without mentioning evolution explicitly
Depth of coverage in uneven across the country
What is scientific classification?
Life forms can be classified according to shared ancestry characteristics, or traits.
Strepsirrhini
Wet- nosed ( like dogs or cats)
Longer snouts
Can produce their own vitamin c
Haplorrhini
Apes, humans
Platyrrhini
Flat nose: new world money’s
Catarrhini
Narrow nose: old world monkeys , apes , humans
Cresting?
Saggital- top of head
Nuchal- near neck muscles
Zygomatic torus
Near cheek bone ( attached to skull)
Supraorbital torus
Brow ridges
Thick brow ridges( bone )
Subnasal prognathusm
How far out the face goes
Dental arcade
The shape made by the teeth in the upper jaw
Diastema
Gap between the canines and incisors
Pectoral girdle
Connects upper limbs to trunk of body
Allows a wide range of movement
Clavicle holds upper limb bones away from
Chest and prices stability to shoulder joints
Sexual dimorphism
When males are larger than females
Can look at overall body size or particular traits
Why is reconciliation important in primate groups?
Important for keeping relationships
We need group for survival
We need to have ways to solve problems
Discuss the notion of religion being vital for teaching morality
People would believe that if they do good things, they will go to heaven.
If you do bad things you’ll get punished, if you do good things you’ll be rewarded
Group living advantaged and disadvantages
Advantages:
- Increased protection
- improve access to food, defend food resources from other groups
- increased access to potential mates
Disadvantages:
- may actually attract predators
- group may have to travel further to find food
- infectious diseases
What is culture ?
Something we are born into
What does grooming do
Bonding , establish and maintain alliances, reconcile conflict , exchange for other resources ( food, sex)
Tool use
Fishing for termites
Using sticks to get honey in trees
Leaves to use as a sponge for water and as a napkin
Sticks and rock to crack open nuts or fruits
What is monogamy?
Each make and female mate with only one member of the opposite sex but offspring are not always fathered by the male in the pair
What is pair bonding
Males do not directly compete over access to females, Instead guard territory, guard mates, and invest in offspring
4 types of locomotives
Verticlal clinging and leaping
Suspension
Quadrupedalisn
Bipedalism
Describe vertical clinging and leaping
Body held upright
Animal grasps trunk of tree
Long, powerful Hind limbs
Describe suspension
Supporting the body using forelimbs to hang beneath branches
Long upper limbs
Describe quadrupedalism
Using four limbs to support body
In trees or on ground
May walk in palms, fingers, or knuckles
Arms and legs approx same length
Describe bipedalism
Standing and moving in two hind limbs
What is new classification?
Based on genetics and evolutionary history
What are hominids
Great apes, humans , and our bipedal ancestors
What are hominins?
Used to refer to us and our ancestors after the split
How to date the divergence?
Molecular clock
As 2 species diverge from a common ancestor, their DNA becomes increasingly different ( random mutations)
Name the 3 early hominins
Sahelanthropus tchadensis (toumai)
Orrorin tugenensis
Aridipithacus ramidus (ardi)
Bipedalism advantages and disadvantages
Advantages:
Appears to be more efficient than quadrupedalism in terms of energy efficiency
Disadvantages:
Puts lots of stress on lower back, hips, knees, feet
Required modification to the skeleton
Childbirth more difficult
Why was the hypothesis of male langur monkeys killing infants wrong?
The males didn’t show any violence when the baby’s were jumping on them and being annoying.
Why do the male langurs kill the babies?
Because they want to have their own baby with a female but if they already have a baby they’re not able to become pregnant if they’re nursing at the same time so the only way they can have a baby with the female is by killing it
What are signs of a monogamy relationship
Carrying the baby to free the mothers hands
Finding food to bring to the female
Small canines
Females lost skin swellings
Cooperative breeding, alloparents
How are bonobos sexual behaviour similar to ours
Sex face to face
Time for pleasure and time for babies
Sex to bond with each other
Same sex sex
What do bonobos use sex for
To break tension
To solve problems
MAke themselves feel better
What are three conclusions on primate cooperation?
- Don’t need to be related
- Based on exchange( will remember act of kindness and will return the favour)
- Empathy
What is altruism
When you act to benefit someone else’s well being sometimes even when it may cost you.
What is mutualistic cooperation?
When you work together towards the same goal that is beneficial to all. Also leads to sharing
How do chimps engage in a from of currency exchange?
They will barter goods such as meat or other services for sex, grooming, or even friendship.
