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Biology 1001 > Cycle 8 > Flashcards

Cycle 8 Flashcards

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
There are things that we call monkeys like old-world money that are more closely related to ________ compared to new-world monkeys
us (no monkeys like apes)
16
Rendezvous 7: Tarsiers (5 species) Rendezvous 8: Lemurs and Lorises (50 species) MRCA of: _______ (63 million years ago)
all primates
16
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:
The problem with the term monkey is that it is a term that does not reflect evolutionary relationships very well
17
Rendezvous 10: Rodents and rabbits ____ are famous for forming new species
Rodents
17
Rendezvous 11: Laurasiatheres Bats, Insectivora, Carnivora, perrisodacltys Spent most of their time on the northern subcontinent of _______
Laurasia
17
Rendezvous 18-22: Lungfish; Coeleacnath; Ray-finned fish; Sharks; Jawless fish ISSUE: _______ MRCA of all vertebrates 530 mya
These ‘fish” are no more closely related to each other than they are to us
18
Other vertebrates Rendezvous 17: Amphibians MRCA of:
all tetrapod's 340 mya
18
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
convergent evolution
18
Some similarities reflect shared ancestors: other similarities reflect:
convergence
19
Rendezvous 15: Monotremes Egg laying mammals MRCA of:
all mammals
19
Rendezvous 16: Reptiles Also, not the best name because:
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
Rendezvous 26: ______ Over 1 million described species Great at forming species
Protosomes
19
Rendezvous 39: ______ Before Last one: back to LUCA
Bacteria
19
Rendezvous 38: _____ Adaptions to extreme environments
Archae
19
Rendezvous 34, 35, 36: Fungi, Amoebozans, Plants ________ has evolved separately in animals, plants, fungi, and ameoenpzpans
Multi-cellularity
19
We can trace our ancestry back to LUCA in just ___ steps
39
19
All life on earth related through:
common descent
20
T/F It matters what we call species
TRUE
21
Why is it important to define how we identify species in the sense of conservation?
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
T/F It matters how we define and identify species
TRUE
22
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.”
Darwin
23
____________ Species = a distinct cluster in phenotypic space. No intermediates or overlap with other clusters
Morphological Species Concept
24
Even though differences in skin color for humans, there are so many ________
intermediates
25
Flaws of biological species concept
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
Over __ species concepts have been proposed
50
27
T/F is a universal species concept
False: Still no universal species concept
28
_________ Species Concept: Reproocutvie isolation and shared gene pool
Biological
29
Two conditions for biological species concept
Freely interbreed under natural conditions Produce viable, fertile offspring
29
For Biological Species Concept: Species = an ______ or potentially _______ group of individuals, reproductively isolated from other such groups
interbreeding
29
Flaws of Biological species concept: (4)
-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
Flaws: of ecological species concept
Ex: Frogs, grow up aquatic but later in life they live on land and breathe through lungs (very different ecology)
30
______ Species Concept Species = a group of organisms that are adapted to a particular set of resources (niche) in the environment
Ecological
31
______ Species Concept Species = group of population with a recent evolutionary history
Phylogenetic
31
The ____ group of populations that are all more closely related to each other than to anything else
smallest
31
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
Biological
31
Flaws: of phylogenetic species concept
Have to work out evolutionary relationships/have to know the phylogeny of the organisms Need a lot of previous knowledge
32
The outcome of secondary contact (depends on: )
when it happens
32
Allopatric speciation (4 steps)
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
______ contact Populations are back in contact
Secondary
32
Secondary contact is or is not needed for speciation
is not
32
May resume interbreeding (_____) - if secondary contact happens early in the speciation process
fusion
33
______ (reproductive barriers exist after fertilization, preventing hybrid offspring from surviving or reproducing)
Postzygotic
33
_______(the separation of different species to keep them from creating offspring by preventing the gates from forming a zygote)
Prezygotic
33
______: selection favors the evolution of prezygotic isolation
Reinforcement
34
Or, may become partly or fully reproductively isolated (if secondary contact happens ____)
later
35
If populations come back into contact, and if postzygotic isolation has already occurred, individuals who don't _____ are favored
hybridize
35
Secondary contact can result in ___ (undoes isolation), OR ____ (accelerates isolation), depending on when it occurs
fusion reinforcement

Biology 1001 (12 decks)

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