Biology Reference
In-Depth Information
An explanation of terms is needed. A gene is a sequence of DNA
along a chromosome that codes for a functional protein or peptide. A
genotype is the combination of genes inherited from the mother and
father in sexual diploid species. In practice, it can refer to either a geno-
type at a single gene locus or the entire set of genes of an individual. A
genome a single set of chromosomes, as found in egg and sperm gam-
etes, but the term has come to be used more broadly to refer to the en-
tire DNA sequence of an individual or even a population, in the case of
genome sequencing.
3.1 Ge ne tic Variation and Behavior
Honey bee workers vary genetically for nearly every trait studied. Ge-
netic variation af ects the distribution of the stimulus-response rela-
tionships of the individuals in a nest, and social organization emerges
through the fundamental self-organizing principles discussed in Chap-
ter 2—the organizational and regulatory logic of the hive. h e polyan-
drous mating behavior of the queen (queens mate with many males)
and the high rate of genetic recombination af ect the behavior of a col-
ony because they af ect the distribution of genetic variation underlying
the response thresholds of workers. h e genotype of an individual con-
strains its behavioral plasticity to environmental change and at the
same time guards against the convergence of behavioral responses that
could occur when individuals share a common environment and expe-
riences. Individuals do still display plasticity in their behavior. Plastic-
ity can arise through changes in the levels of behavior-releasing stimuli
that are encountered or through the modii cation of the response
thresholds of individuals as a consequence of experience or develop-
ment. Some traits show considerably more plasticity at the individual
level that in turn af ects colony-level plasticity and resilience.
Plasticity and resilience need more explanation. Plasticity is the abil-
ity of an individual or a colony to change its behavior or social structure
in response to an internal (physiological) or external (environmental)
stimulus. For example, a colony increases its number of water foragers
in response to an increase in hive temperature, while individuals
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