M+Ms

Last Friday in class we turned in our Natural Selection Lab and our 4 Corners vocabulary squares. Then we talked more about natural selection and how it works and how camoflague plays an important role in some types of natural selection. We also took a pretest that didn't count with a partner. Then we took some notes.
Today in class we handed in our flow map and got a stamp for doing the U.P. 33-36. We also got our Natural Selection Lab back and our 4 Corners Vocabulary Squares back. We then took down some notes and watched a short part of a video. After the video, we did an M+M Lab and took data. The M+Ms represented atoms.

Notes-

ANATOMICAL EVIDENCE

comparative anatomy- study of similarities and differences between organisms

• homologous structures
• analogous structures
• vestigial organs

HOMOLOGOUS STRUCTURES

as similar organisms adapt to different environments, the function of their appendinges changed

• a bird's arms became wings to flap
• a human's arm is used to hold things

ANALOGOUS STRUCTURES

different organisms began living in similar environments, their appendages evolved to preform the same function

• a butterfly has wings to fly that are made from an exoskeleton
• a sparrow has wings to fly that are made from an endoskeleton

VESTIGIAL STRUCTURES

structures which remain in organisms but have no obvious function

• leg bones in snakes and whales
• appendix in humans
• ear muscles in humans

COMPARATIVE EMBRYOLOGY

organisms with similar embryos are though to be more closely related

BIOCHEMICAL EVIDENCE

chimp and human hemoglobin are VERY similar

GENETIC VARIATION

in terms of genetics evolution is the change in frequency of alleles in populations gene pools.

natural selection leads to change in gene frequency.

GENETIC DRIFT

changes in the gene pool of a small population due to change.

Occurs when a small group colonizes a new habitat-founder effect

SPECIATION

species- group of organisms that interbreed to produce fertile offspring under normal conditions

gradualism- change in species is slow and steady

punctuated equilibrium- long periods of stability followed by short periods of rapid change

SPECIATION-ISOLATING MECHANISMS

for new species to form reproductive isolation need to occur

organisms don't interbreed

-gene pools become separate

• behavioral
• geographic
• temporal

ADAPTIVE RADIATION

a single species evolves into many species

often occurs when a niche opens up

CONVERGENT EVOLUTION

organisms come to resemble one another but evolved differently

source of analogous structures

examples

• dolphins and sharks
• marsupials and mammals

COEVOLUTION

organisms with close ecological relationships evolve together

• pollinators and flowers
• poisonous plants and insects

RELATIVE DATING

used to ESTIMATE the age of fossils

older fossils are in deeper layers of rock

determines the absolute age

radioactive elements decay at a steady rate

ANCIENT EARTH

atmosphere was compsed of gases

earth formed about 4.6 million years ago

FIRST ORGANIC MOLECULES

1950's Miller and Urey reproduced conditions of ancient Earth

electric sparks simulated lighting

AAs began to form

HOMEWORK

pg. 31-32

26.3 check my understanding due weds

test Friday

T.V. ad-2/28

Next Scribe is Omar