bio lab evolution Flashcards
If the world’s history were compressed into one hour, what kind of life appeared during the first 50 minutes?
single-celled organisms
Last 10 minutes?
animals
Last 0.01 second?
humans
How long ago did mammals first appear on Earth?
200 million years ago
3 physical traits mammals have in common that relate to living on land?
- reproduction; live birth
- warm blooded
- breathe air
3 physical traits mammals have in common that relate to living on land?
- reproduction; live birth
- warm blooded
- breathe air
What type of animals did the Creodont skull that Dr. Gingrich discovered resemble?
wolf, where its walnut size bump was unusual
Transitional Form
Fossils or organisms that show the intermediate states between an ancestral form and that of its descendants
Whale Valley is an archeological site located in the Sahara Desert. How could there be whale skulls here?
This area used to be the sea. It was a protected bay away from sea.
What Vestigial structure did the basilosaurus have that modern whales do not?
they had complete set of leg bones= 4 legged animal
Theory of Transformation: Sinonyx (wolf-like) to the Whale?
It lived and hunted around sea were it used water as food source. Its front legs became fins and back legs+ furs disappeared = fish like
How do fish swim?
flexing spine side to side
How do otters, whales, and land mammals swim?
undulating spines up and down
Tetrapods
4 limbed vertebrates
Why did the paleontologist search for tetrapods fossils in Pennsylvania ? What unusual feature did they find at tetrapods limbs and what is this evidence of?
-Rocks+ hills right age
-Small shoulder bone
-earliest tetrapods rising from the water
How do the bones of the early tetrapods fish resemble ours, like Acanthostega?
Hand=forelimb
Digit fingers= petal shaped hands
Fish Adaptations
have elaborate defenses like shield- hard shell
What advantage did the first limbs with digits provide?
way to get out of water w/o attracting predators
Cambrain Explosion
fossils of all diversity and animals came out of no where
Trilobites? What are there descendants?
Arthropods w/ external skeleton. Crabs, lobsters, insects, and spiders
What makes the fossils of the Burgess Shale so important in studying evolution?
earliest animals of all creatures with skeletons
The pikaia is the earliest ancestors of all vertebrate animals. Why?
has internal nerve cord resembling a spine
How do all embryos start out?
cluster of almost identical cells
A scientist, Dr. Bateman, was studying similar segmentation patterns of animals. What mutations did he observe that related to these segmentation patterns?
antlers, crab claws
How do segmentation patterns relate to DNA
resembled segmented organization of genes in DNA (responsible for segmentation trait common in most animals)
How could mutations be purposely caused with fruit flies?
adding poison and radiation to disrupt DNA structure
What does antennapedia gene control ? What happens if it misfires?
controls growth of antenna on head and misfires= growth in thoracic area
When the mouse “eyeless” gene was implanted into fruit flies, what happened? What implications does this have for study of evolution?
-fruit fly had no eyes
-mistakes can happen if genes are wrong
3 Lemur Movements
- Flexible spines to climb trees
- Leaping in upright position
- Walk on all 4 legs
What primate is the closest living relative to humans ? Why?
Chimpanzee= same # of bones placed nearly same way + DNA nearly identical
What type of movements do chimpanzees rely on that humans don’t?
walking on knuckles
Humans: Spinal Column, Pelvis, Position of Knees
-based skull pointing downwards
-short+squat
-close together
Chimpanzees: Spinal Column, Pelvis, Position of Knees
-back of skull
-long, narrow
-wide apart
