Transcript viking.lkstevens.wednet.edu

Are these the same species?
How do you know?
Are these the same species?
How do you know?
Are these the same species?
In some cases, it is enough to look at two
individuals and be able to tell visually that they
are different species.
But, we should have a better answer!
Are these the same species?
How do you know?
Are these the same species?
How do you know?
Are these the same species?
How do you know?
Are these the same species?
● Can they reproduce?
● Are they genetically similar? Are there
similarities in their DNA?
DNA
● Scientists can extract a DNA sample from
the organisms cells that they are hoping to
compare.
● In general: the more closely related, the
more genetic similarities (= more similarities
in DNA).
DNA
Rank the following. Number 1 will have the
most DNA similarities and number 7 will have
the fewest
● A human and a chimpanzee (different species)
● Identical twins
● Siblings
● Fraternal twins
● Two unrelated humans
● A human and a shark
Reproduction
● Temporal isolation
o
o
Different habitats
Mating at different times
● Behavioral isolation
o
Different mating rituals
● Mechanical isolation
Reproduction
● Zygote mortality
o
Miscarriage
● Non-viability of hybrid
o
Offspring can’t reproduce
 Donkey + horse = mule
 Tiger + lion = liger