Cycle 8 Flashcards

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1
Q

Around _____ new species are discovered each year

A

18000

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2
Q

Sometimes we find evidence of new species that are already ______ (ex burrowing dinosaurs)

A

extinct

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3
Q

___ million describes species of eukaryotes that we know of

A

1.2

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3
Q

The fact that we keep discovering new species a year suggests that:

A

there are a lot of species out there that we don’t know about

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4
Q

Estimated that in terms of eukaryotic species globally is around ___ million (give or take 1.3 million)

A

8.7

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5
Q

_________ proposed universal common descent for all life on earth

A

Origins of Species

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6
Q

For every combination of species, there is a _____________ (MRCA)

A

most recent common ancestor

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7
Q

LUCA stands for

A

Last Universal Common Ancestor (LUCA)

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7
Q

LUCA was ____ the first living thing

A

NOT

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8
Q

Was or Was not the only thing living at the time

A

WAS NOT the only thing living at the same time but those individuals did not go off and split off

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9
Q

Would LUCA have ancestors of their own?

A

YES (Those individuals are also common ancestors but not the most recent)

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10
Q

Branching points on the Tree of Life -> rendezvous points (______)

A

speciations

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10
Q

If we go back far enough in time. Any ___ individuals will share a common ancestor

A

two

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11
Q

At some point, ________. Some of your ancestors on your mom’s side are also ancestors on your dad’s side.

A

pedigrees collapse

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11
Q

“Rendezvous Zero” _____ of all humans

A

MRCA

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11
Q

Rendezvous 4: Gibbons
MRCA of:

A

all apes

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12
Q

How long ago did the most recent common ancestor of all modern humans live?

A

Around 3000 years (100 generations)

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13
Q

T/F Almost every human on earth is your 50th cousin or closer

A

TRUE

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13
Q

Rendezvous 1: Chimps and bonobos

Are Chimps and bonobos more closely related to each other or us?

A

Chimps and bonobos are more closely related to each other than us

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14
Q

We as humans are _____ as closely related to chimps and bonobos

A

equally

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14
Q

Rendezvous 2: Gorillas
The next closest evolutionary cousins are gorillas
MRCA of:

A

African great apes

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14
Q

Rendezvous 3: Orang utangs
Great apes but, they don’t live in Africa, they live in Asia
MRCA of:

A

of all great apes

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14
Q

________ mass extinction, 65 mya

A

End-Cretaceous

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15
Q

“If we are descended from chimpanzees, why are there still chimpanzees around?”

A

FALSE: we are not descended from chimps, the most common ancestor that lived around 5-6 million years ago was not a chimpanzee, bonobos or humans
We all evolved

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16
Q

There are things that we call monkeys like old-world money that are more closely related to ________ compared to new-world monkeys

A

us (no monkeys like apes)

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16
Q

Rendezvous 7: Tarsiers (5 species)
Rendezvous 8: Lemurs and Lorises (50 species)
MRCA of: _______ (63 million years ago)

A

all primates

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16
Q

Rendezvous 5,6: Old World and New World monkeys
Around 25 million years ago we met up with 100 species of what we call old-world monkeys
The problem is:

A

The problem with the term monkey is that it is a term that does not reflect evolutionary relationships very well

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17
Q

Rendezvous 10: Rodents and rabbits
____ are famous for forming new species

A

Rodents

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17
Q

Rendezvous 11: Laurasiatheres
Bats, Insectivora, Carnivora, perrisodacltys
Spent most of their time on the northern subcontinent of _______

A

Laurasia

17
Q

Rendezvous 18-22: Lungfish; Coeleacnath; Ray-finned fish; Sharks; Jawless fish
ISSUE: _______
MRCA of all vertebrates 530 mya

A

These ‘fish” are no more closely related to each other than they are to us

18
Q

Other vertebrates
Rendezvous 17: Amphibians
MRCA of:

A

all tetrapod’s 340 mya

18
Q

endezvous 14: Marsupials
Provide cool examples of ________
Not similar to moles because they’re close relatives, but instead we can see how features are similar due to their environment

A

convergent evolution

18
Q

Some similarities reflect shared ancestors: other similarities reflect:

A

convergence

19
Q

Rendezvous 15: Monotremes
Egg laying mammals
MRCA of:

A

all mammals

19
Q

Rendezvous 16: Reptiles
Also, not the best name because:

A

There are things that we call reptiles like lizards or snakes that are more closely related to birds compared to other reptiles like turtles

19
Q

Rendezvous 26: ______
Over 1 million described species
Great at forming species

A

Protosomes

19
Q

Rendezvous 39: ______
Before Last one: back to LUCA

A

Bacteria

19
Q

Rendezvous 38: _____
Adaptions to extreme environments

A

Archae

19
Q

Rendezvous 34, 35, 36: Fungi, Amoebozans, Plants
________ has evolved separately in animals, plants, fungi, and ameoenpzpans

A

Multi-cellularity

19
Q

We can trace our ancestry back to LUCA in just ___ steps

A

39

19
Q

All life on earth related through:

A

common descent

20
Q

T/F It matters what we call species

A

TRUE

21
Q

Why is it important to define how we identify species in the sense of conservation?

A

ESA (in the USA) SARA (in Canada) and IUCN (global) provide stronger legal protection for conserving endangered species than for conserving endangered subspecies or populations

21
Q

T/F It matters how we define and identify species

A

TRUE

22
Q

Who said: “No one definition (of species) has as yet satisfied all naturalists; yet every naturalist knows vaguely what (they) mean when (they speak of a species.”

A

Darwin

23
Q

____________
Species = a distinct cluster in phenotypic space. No intermediates or overlap with other clusters

A

Morphological Species Concept

24
Q

Even though differences in skin color for humans, there are so many ________

A

intermediates

25
Q

Flaws of biological species concept

A

Flaws:
Black bear, rare has white fur (mother and colour look different, but not true)
Sexual dimorphism (female and male look different, no intermediates)
Appearance varies through lifetime (like tadpoles to frogs)
Discrete/discontinuous variation in morphology presence problems for this concept
There can be groups of organisms that look similar but they can tell each other apart (makes more sense to consider them two different species)

26
Q

Over __ species concepts have been proposed

A

50

27
Q

T/F is a universal species concept

A

False: Still no universal species concept

28
Q

_________ Species Concept: Reproocutvie isolation and shared gene pool

A

Biological

29
Q

Two conditions for biological species concept

A

Freely interbreed under natural conditions
Produce viable, fertile offspring

29
Q

For Biological Species Concept:

Species = an ______ or potentially _______ group of individuals, reproductively isolated from other such groups

A

interbreeding

29
Q

Flaws of Biological species concept: (4)

A

-Cannot use the concept on organisms that reproduce entirely asexually
-We find potential new species, but they are not alive (cannot tell who mates with who with just fossils)
-Ring species
At most points along the ring, few populations are willing to mate with others, but at one point in the ring, individuals are not willing to mate with another group
Depending on where you go to study mating interactions, you will
get different conclusions

-Also, issue if two populations are fully allopatric
If their geographic range doesn’t overlap with each other
Geographically separated, so will never know if would naturally mate

29
Q

Flaws: of ecological species concept

A

Ex: Frogs, grow up aquatic but later in life they live on land and breathe through lungs (very different ecology)

30
Q

______ Species Concept
Species = a group of organisms that are adapted to a particular set of resources (niche) in the environment

A

Ecological

31
Q

______ Species Concept
Species = group of population with a recent evolutionary history

A

Phylogenetic

31
Q

The ____ group of populations that are all more closely related to each other than to anything else

A

smallest

31
Q

Baltimore and Bullock’s orioles look different, and they are not each other’s closest relatives. They interbreed where their ranges overlap, and produce hybrid offspring of normal fitness. Which of the species concepts below would consider these birds as belonging to the same species?
Moprholcial
Biological
Phylogenetic

A

Biological

31
Q

Flaws: of phylogenetic species concept

A

Have to work out evolutionary relationships/have to know the phylogeny of the organisms
Need a lot of previous knowledge

32
Q

The outcome of secondary contact (depends on: )

A

when it happens

32
Q

Allopatric speciation (4 steps)

A

1) Single population
2) Becomes separated (ex river, highway, mountain)
3) Populations diverge (ex difference in selection pressure or genetic drift)
The longer they are separated, the more they diverge
All that is needed for speciation to happen
4) SOMETIMES: Secondary contact

32
Q

______ contact
Populations are back in contact

A

Secondary

32
Q

Secondary contact is or is not needed for speciation

A

is not

32
Q

May resume interbreeding (_____) - if secondary contact happens early in the speciation process

A

fusion

33
Q

______ (reproductive barriers exist after fertilization, preventing hybrid offspring from surviving or reproducing)

A

Postzygotic

33
Q

_______(the separation of different species to keep them from creating offspring by preventing the gates from forming a zygote)

A

Prezygotic

33
Q

______: selection favors the evolution of prezygotic isolation

A

Reinforcement

34
Q

Or, may become partly or fully reproductively isolated (if secondary contact happens ____)

A

later

35
Q

If populations come back into contact, and if postzygotic isolation has already occurred, individuals who don’t _____ are favored

A

hybridize

35
Q

Secondary contact can result in ___ (undoes isolation), OR ____ (accelerates isolation), depending on when it occurs

A

fusion
reinforcement