3 Flashcards
(16 cards)
Adaptive traits
hereditary characteristics that make organisms more likely to survive and reproduce under a given set of environmental conditions.
spontaneous selection
Spontaneous mutations — random genetic changes that happen naturally.
Spontaneous mutation: One beetle randomly mutates and turns green instead of brown. It wasn’t planned — it just happened!
Natural selection: In their environment, green beetles are harder for birds to see 🦅, so they survive and have more babies. Over time, most beetles in the population become green because the green ones survive better.
hereditary selection
If faster deer 🦌 survive predators better, and speed is a hereditary trait (passed through genes), then natural selection will favor fast deer. Over generations, the population becomes faster.
In short:
👉 Hereditary selection = natural selection, but specifically acting on traits passed by genes.
artificial selection
Artificial selection is when humans choose which traits they want in plants or animals and breed them for those traits. 🧑🌾🐕
Suppose that each species of Galápagos tortoise has a distinctive shell and that variations in shell size make some tortoises better adapted for defence. Imagine an island where many hunt these tortoises. Individuals with a larger shell would be more likely to survive and reproduce than would tortoises with smaller shells. These favoured individuals would pass on the genes that produce larger shells to their descendants, while those with smaller shells would not reproduce, leading to extinction. Which of the following would most likely drive this event?
natural selection
What critical piece of knowledge was Darwin missing when he formulated his theory of evolution through natural selection?
He did not know about Mendelian inheritance
What are homologous traits?
characteristics that are similar in two species because they inherited the genetic basis of the trait from their common ancestor
analogous traits
Analogous traits are traits that look or function similarly in different species but evolved independently, not from a common ancestor.
Which of the following is one correct interpretation of the wings of bats and the wings of birds?
They are homologous because they have a similar internal bone structure inherited from a common ancestor.
Which of the following is the reason for existence of vestigial structures (seemingly useless parts of the body)?
They must have functioned in ancestral organisms.
Extinct glyptodont and living nine-banded armadillo were related according to Darwin. In what way are they related?
Glyptodont is an ancestor and armadillo is a descendant.
Who proposed that species change through time?
Charles Darwin, Jean Baptiste de Lamarck, and Alfred Russel Wallace
What was a basic truth of inheritance that had been known well before Darwin’s time?
Offspring frequently resemble their parents and selective breeding improves domesticated plants and animals.
The ability of the bacterium E. coli to adapt to different growth temperatures is an excellent example of which of the following?
A) experimental evolution
B) prokaryotic evolution
C) adaptive transformation
D) genetic transformation
A
Adaptive transformation -
👉 Adaptive = better suited to the environment.
A population of rabbits 🐇 in a snowy area slowly becomes whiter over generations because white rabbits survive better (they’re camouflaged).
l
