Chapter 3

Front 1

creationism

Back 1

biological similarities and differences originated at the Creation; characteristics of life forms were seen as immutable--they could not change

Front 2

Carolus Linnaeus

Back 2

developed the first comprehensive classification, or taxonomy, of plants and animals

Front 3

catastrophism

Back 3

fires, floods, and other catastrophes, including the biblical flood had destroyed ancient species; after flood, God created again leading to contemporary species

Front 4

evolution (transformism)

Back 4

alternative to creationism and catastrophism; species arose from others through a long and gradual process of transformation, or descent with modification

Front 5

uniformitarianism

Back 5

the present is the key to the past; necessary building block of evolutionary theories

Front 6

natural selection

Back 6

explained the origin of species, biological diversity, and similarities among related life forms

Process by which nature selects the forms most fit to survive and reproduce in a given environment

Front 7

strategic resources

Back 7

necessary resources for life such as food and space

Front 8

genetics

Back 8

help understand the causes of biological variation

Front 9

Mendelian genetics

Back 9

studies the ways in which chromosomes transmit genes across generations

Front 10

biochemical genetics

Back 10

examines structure, function and changes in DNA

Front 11

population genetics

Back 11

investigates natural selection and other causes of genetic variation, stability, and change in breeding population

Front 12

dominant

Back 12

trait could mask the other form in mixed individuals

Front 13

recessive

Back 13

traits would appear in unaltered form in later generations because genetic traits were inherited as descrete units

Front 14

chromosomes

Back 14

arrnaged in matching pairs; carry information; humans have 46 arranged in 23 pairs, half of pair from mother, 1/2 from father

Front 15

gene

Back 15

determines wholly or partially a particular biolobical trait

Front 16

alleles

Back 16

biochemically different forms of a given gene

Front 17

heterozygous

Back 17

mixed offspring

Front 18

homozygous

Back 18

possessing two identical alleles of a gene

Front 19

genotype

Back 19

hereditary makeup; what you really are genetically

Front 20

phenotype

Back 20

expressed physical characteristics; what you appear as

Front 21

independent assortment

Back 21

traits are inherited independently of one another

Front 22

recombination

Back 22

important in biological evolution because it creates new types on which natural selection can operate

Front 23

zygote

Back 23

fertilized egg

Front 24

mitosis

Back 24

ordinary cell division which continues as the organism grows

Front 25

meiosis

Back 25

special process by which sex cells are produced; four cells are produced from one instead of 2 from 1

Front 26

gene pool

Back 26

all the alleles and genotypes within a breeding population

Front 27

genetic evolution

Back 27

change in gene frequency, that is, in the frequency of alleles in a breeding population from generation to generation

Front 28

mechanism of genetic evolution

Back 28

include natural selection, mutation, random genetic drift, and gene flow

Front 29

adaptive

Back 29

most favored by natural selection in that environment will be selected again and again from generation to generation

Front 30

directional selection

Back 30

long-term selection of the same trait(s)

Front 31

sexual selection

Back 31

based on differential success in mating; the term for this process i which certain traits of one sex are selected because of advantages they confer in winning mates

Front 32

sickle-cell anemia

Back 32

individuals whoa re homozygous for Hb^S; red blood cells are shaped like crescents; interferes with the blood's ability to store oxygen

Front 33

mutations

Back 33

occur spontaneously and regularly; changes in the DNA molecules of which genes and chromosomes are built

Front 34

random genetic drift

Back 34

change in allele frequency that results not from natural selection but from chance

Front 35

gene flow

Back 35

exchange of genetic material between populations of the same species; works in conjunction with natrual selection by providing variety on which selection can work

Front 36

species

Back 36

a group of related organisms whose members can interbreed to produce offspring that can live and reproduce

Front 37

speciation

Back 37

generally prvented by gene flow; formation of new species

Front 38

approaches to study of human biological diversity

Back 38

1. racial classification
2. current explanatory approach

Front 39

racial classification

Back 39

attempt to assign humans to discrete categories based on common ancestry

Front 40

clines

Back 40

shifts in gene frequencies between neighboring groups

Front 41

melanin

Back 41

primary determinant of human skin color; chemical substance manufactured in the epidermis or outer skin layer

Front 42

tropics

Back 42

belt extending about 23 degrees north and south of the equator where most dark skinned people lived in the 16th century

Front 43

rickets

Back 43

nutritional disease; softens and deforms the bones as a result of a stortage of vitamine D diminishing the absorption of calcium in the intestines

Front 44

hypervitaminosis D

Back 44

a potentially fatal condition caused by too much vitamin D; calcium depostis build up in the body's soft tissues

Front 45

phenotypical adaptation

Back 45

adaptive changes occur during the individual's lifetime; made possible by our ability to change in response to the enviornments we encounter as we grow(plasticity)