Biology, Biologists, and Biosciences Keywords
Ages of sand
The Ages of Sand, as described by Douglas Adams, explains the scientific revolution and
the start of modern science in terms of 4 different stages. It is especially relevant to the
natural sciences. The 1st stage (1608) involves the telescope, where sand was moulded
into glass and the glass was used to make lenses to look at distant planets and events. The
2nd stage (1678) involves the microscope, which allowed us to observe micro organisms
that have never been seen before. The 3rd stage (1961) involves the computer chip / silica
chip. Computational skills were automated into calculating machines and more
computations can be computed as it becomes more powerful. This digitalized the
knowledge base of the world and allowed everything to be retrievable. The 4th age
(1980s) involves fibre optics which allow the movement of information at lightning
speeds and allows for international collaboration in science.
An analogy is a trait or an organ that appears similar in two unrelated organisms and are
often the result of convergent evolution. Another term for this phenomenon is homoplasy
(from the Greek for 'same form'), where structures function in the same / common way,
but it does not have the same evolutionary origin. For example, the wing of an insect and
the wing of a bat have the function of flying, but have evolved through different
mechanisms and from different common ancestors. Analogous characters are
homoplasious, phenotypic similarities that evolved independently in different lineages.
A binomen involves the name of the genus (the noun) and the species (the adjective). The
binomen is in Latin. The first letter of the genus name is capitalized. Some conventions
of the binomen include using italics when typing the binomen name or underlining it
when writing the name out. For example, the honey bee is called Apis mellifera. A
binomen name is part of binomial nomenclature.
*see binomen above*
Biogeography is the study of the distribution of species, organisms, and ecosystems in
space and through geological time. Biogeography unites concepts and information from
ecology, evolutionary biology, geology, and physical geography. Comte du Buffon starts
the concept of biogeography as he makes observations while travelling and collecting.
Continental drift is biogeography on a world scale.
The catastrophe theory was proposed by Cuvier to explain why he found animals in the
sediment of the earth that do not exist now. It explains fossils, bones, and missing
organisms (extinction) and the survivors (organisms that exist now). In the Bible, the
catastrophe theory can be explained as Noah's flood. Many of the geological features of the earth and the past history of life could be explained by catastrophic events that had
caused the extinction of many species of animals. Over the course of his career Cuvier
came to believe that there had not been a single catastrophe but several, resulting in a
succession of different faunas.
As described by Schleiden and Schwann, the cell theory states that:
1) All living things in the world are made of cells; individual cells have all the
characteristics of life
2) Cells are the smallest divisible unit (this is why single-celled organisms can still live);
the cell is the fundamental unit of structure and function in living organisms
3) Cells come from the division of other cells (life comes from life)
A chronological prediction predicts that something will happen in the future. It is
prediction in a general use in the general public.
Cladograms are phylogenetic (the evolutionary relatedness) trees produced by cladists.
It is used in cladistics which is a method of classifying species of organisms into groups
called clades, which consist of an ancestor organism and all its descendants.
The theory of common ancestry was proposed by Charles Darwin and was one of the
theories that was almost immediately accepted. He proposes that there is a common
ancestry between species and that ancestry is a branching pattern rather than a linear
patter as proposed by Lamarck. Common ancestry looks for structures that are shared
between organisms, its anatomy, and its morphology. If organisms have physical
similarities, they could be related. Common ancestry looks at comparative anatomy
(homology), comparative embryology, vestigial structures, and molecules containing
Constancy of species
The theory of no constancy of species was proposed by Charles Darwin and was one of
the theories that was almost immediately accepted. He proposes that species are not
always identical and will change over time. This theory was proven by fossils where
transitional fossils of intermediate animals have been found. The fossil is record is
constantly being filled in. Extinction proves that there is no constancy in species. There
have been at least 5 major. The transition of the hyracotharium to the horse is proof that
there is no constancy in species and organisms change over time.
A component of experimental design. Convergent evolution
Convergent evolution refers to more distantly related organisms, parallel to more closely
related ones. Convergent evolution describes the acquisition of the same biological trait
in unrelated lineages. It is related to homoplasy and analogy in that these terms describe a
structure of an organism that functions in the same way but don't have the same
A -> S
Cuvier (Georges) 1769-1832
Georges Cuvier, a palaeontologist and zoologist, realized that the layers of fossils
represented organisms that had lived at successive times in the past. He suggested that
abrupt changes between geologic strata marked dramatic shifts in ancient environments.
Cuvier develops catastrophism (catastrophe theory) reasoning that each layer of fossils
represented the remains of organisms that had died in a local catastrophe such as a flood.
Somewhat different species then recolonized the area, and when another catastrophe
struck, they formed a different set of fossils in the next higher layer.
Darwin (Charles) 1809-1882
Charles Darwin, after sailing on the HMS Beagle around South America, proposes that
variation comes from population groups and changes come from the amount of variation
in a population; some of this variation is successful and is passed on through breeding.
He says that the scala naturae doesn't exist and that there has been change over time. His
5 theories on evolution postulate no constancy of species, a common ancestry, gradual
changes, multiplication of species, and natural selection. His On the Origin of Species, he
proposes a logical mechanism for evolutionary change.
Darwin (Erasmus) 1731-1802
Erasmus Darwin was the grandfather of Charles Darwin and a physician. He translates
Linnaeus' work into English. He proposes that there is a transformation in organisms over
time and that the scala naturae does not fit, even going on to propose that perhaps man is
the descendent of other mammals. His poem The Temple of Nature describes the
transformation of a single celled organism into a multicellular organism.
Deduction deals with reasons from the general to the specific. It works up from the laws.
and variables can be examined. For example, all insects have wings and this animal is an
insect, therefore this animal has wings. Physical science uses deductive reasoning.
Descent with modification
Darwin argued that all the organisms that have ever lived arose through descent with
modification; the evolutionary alteration and diversification of ancestral species. Darwin
proposed natural selection as the mechanism that drives evolutionary change. Divergent evolution
Divergent evolution is the accumulation of differences between groups which can lead to
the formation of new species, usually a result of diffusion of the same species to different
and isolated environments which blocks the gene flow among the distinct populations
allowing differentiated fixation of characteristics through genetic drift and natural
The domain is the highest taxonomic rank. All life on earth can be classified into 3
domains which are the archaea (single-celled prokaryotes), bacteria (single-celled
prokaryotes), and the eukarya
Empirical observations are dependent on evidence or consequences that are observable
by the senses. The physical sciences use empirical observations and thus, empirical
observations can be deduced from a law.
A philosophy that states that an organism contains the essence of life with no chance for
change and will not be promoted along the scala naturae.
Eukarya is a group belonging to the taxonomic rank of the kingdom. The word comes
from the Latin 'eu' meaning true and 'karyote' meaning seed, referring to the nucleus. The
eukaryote contains complex structures within its membrane.
An evolutionary tree is also known as a phylogenetic tree. They present phylogenies
(evolutionary histories of a group of organisms). Phylogenetic trees are formal
hypotheses identifying likely relationships among species. Phylogenetic hypotheses allow
us to distinguish similarities inherited from common ancestors in contrast to those that
evolved independently in response to similar environments.
Extinction is a concept first proposed by Cuvier which involves the death of the last
individual in a species or the last species in a lineage. Cuvier's catastrophe theory was
thought to have explained the reason for missing organisms. There have been at least 5
major extinctions in the world.
Facts are theories that have undergone thorough testing. Facts are rooted in theories that
are sound. Conclusions that answer your thesis can be seen as fact. Fitness
Fitness describes the ability to both survive and reproduce, and is equal to the average
contribution to the gene pool of the next generation that is made by an average individual
of the specified genotype or phenotype. If differences between alleles at a given gene
affect fitness, then the frequencies of the alleles will change over generations; the alleles
with higher fitness become more common. This process is called natural selection and is
key in the evolutionary process.
The fossil record is the collective accumulation of artifacts which have been fossilized all
over the world. When viewed as a whole, the fossil record can provide interesting
information about the evolution of life on Earth.
The germ theory states that diseases come from germs and micro organisms. The germ
theory contrasted the theory of spontaneous generation. Louis Pasteur confirmed this
theory using the experiments involving broths. He exposed freshly boiled broth (killing
all organisms first) to air in a vessel that contained a filter to stop particles. Nothing grew
in the broths, and therefore, he confirmed that the living organisms that grew in such
broths came from the outside rather than generate spontaneously.
A historical narrative is a descriptive piece of writing and is the source of information
and results in the natural sciences, in contrast to the use of laws in the physical sciences.
Historical narratives are used to answer the why questions in ultimate causes. For
example, historical narratives may describe genetic and evolutionary history or may be
used to explain why organisms are the way they are. Darwin's The Origin of Species is a
Homology was the basis of comparative anatomy, used to demonstrate Darwin's theory of
common ancestry. Over evolution, a structure may not look like it did in the common
ancestor but has because it has been modified to the environment it is used to, yet the
structures share common bone structure. An example of homologous structures are the
human arm and the whale flipper.
Homoplasy is the similarity in species of different ancestry and is a result of convergent
evolution. In homoplasy, a structure functions in the same way but does not have the
same evolutionary origin. For example, the wing of an insect and a wing of a bat both
serve the purpose of flying, but they have evolved through different mechanisms and
from different common ancestors.
Huxley (Julian) 1887-1975
Huxley proposes the synthetic theory of evolution, involving population genetics and
natural selection based on Mendelian genetics. He takes Mendel's punnet squares and applies it to population genetics (i.e.: Hardy-Weinberg Equilibrium). This describes the
origins of variation and understanding of how genes change and flow in a population.
Furthermore, he applies theories of biogeography to his works and proves Buffon's
theories via a genetic and molecular base.
A part of thorough scientific process. A hypothesis is essentially a baby theory. It is a
statement made that tests the thesis. It tests small elements of the concepts involved in the
theory and it further develops the theories.
Induction and inductive reasoning constructs or evaluates propositions that are
abstractions of a large amount of observations. It is commonly construed as a form of
reasoning that makes generalizations based on individual and specific instances. It is
contrasting with deduction. Natural science is an inductive science.
Lamarck (Jean-Baptiste) 1744-1829
Lamarck was the first person to de