BIOL10004 Chapter Notes - Chapter links 1-11: Gynoecium, Ftsz, Polysaccharide
Lecture readings ( links 1-22)
❖ 1
➢ Species are decreasing at a real fast rate due to human intervention biodiversity
crisis
➢ Endemic: have evolved at one place and occur nowhere else
➢ Origin of life 3.5 BN -4 BN yrs. ago
❖ 2
➢ phylogeny: pattern of branching depicting evolutionary relationships can be the
basis for hypothesising how organisms have evolved. Aided by comparative
morphology.
➢ cladistics analysis: comparative method of discovering the ordering on the branches
of a phytogenic tree
➢ primitive character: plesiomorphic
➢ advanced character which are considered to have evolved more recently:
apomorphic
➢ synamorphies: shared advanced characters
➢ apomorphies: own unique characters due to evolutionary change after divergence
similarities of early embryonic stages indicate that all vertebrates share a
fundamental step in their developmental program. Modification of the later stages
of development accounts for the great diversity of form within the vertebrates
➢ Concept of homology: all life is based on the same fundamental principle. Unity
believed that homologies existed between adult parts of animals as diverse as
molluscs, insects and fishes,
➢ Biologists of toda see a uit of pla o uit of opositio at the oleula
level because of the universal occurrence of DNA
➢ Vestigial organs: no apparent function, clues to evolutionary relationships when
comparing organisms. Its function was present in ancestors prediction
➢ Fossil record supplies evidence of both the forms of life in the past and their
geological ages. is no way of knowing whether a fossil is a direct ancestor of a more
recent species or represents a related line of descent (lineage) that simply became
extinct.
➢ Homologous features are evidence of relationships between divergent forms
▪ Divergent evolution is the evolution of different species from a common
ancestral species. Evidence comparative morphology
▪ Structures that have the same basic plan but different function: homologous.
Common inheritance
➢ Analogous features are evidence of convergence
▪ The independent development of similar structures in unrelated or distantly
relate organism often in the same environment convergent evolution
▪ Species within a genus can independently evolve similar features (parallel
evolution)
find more resources at oneclass.com
find more resources at oneclass.com
2
▪ Only homologous data should be used to create phylogenies
➢ Homologues exists at molecular level. Studying DNA by sequencing to compare at
molecular level
➢ Sequence of amino acids in polypeptide chain genetic info and evolutionary
history of an organism
➢ To determine which characters are phylogenetically informative, sequences are
compared with those of an outgroup, a related organism that is outside the group
being studied. In DNA analysis, A, T, C or Gs that are in common with the outgroup
must have been inherited more distantly and are, therefore, considered
plesiomorphic. Nucleotides that are different must have evolved within the ingroup
and are considered apomorphic and potentially informative.
➢ NA sequences evolve at different rates.
➢ Regions of DNA where base substitutions accumulate rapidly are useful for studying
the phylogeny of closely related organisms.
➢ Highly conserved regions, such as nuclear genes that encode for ribosomal RNA, can
be used to study organisms dating back to the origin of life, four billion years ag
➢ transversion: changes between purines and pyrimidines (occur less frequently
➢ genome of chloroplast: cpDNA
❖ 3
➢ classification is important for info storage and retrieval and predict new information
as the classifications reflect the order that exists in nature
➢ taxonomy: methods and principles of classification, naming taxa is governed by
codes of nomenclature.
➢ Rank order
▪ Kingdom
▪ Phylum
▪ Class
▪ Order
▪ Family
▪ Genus
▪ Species
➢ Monophyletic: include entire branch
▪ Moophleti tao: iludes all desedats lieages fo a oo aesto
▪ Paraphyletic: excludes some descendants
▪ Polyphyletic: includes unrelated lineages
▪
➢ binomial system: name of each kind of organism consists of two parts : genus and
species and are useful for unambiguous communication about organisms
➢ As a taxon, the term ‘species’ refers to the lowest classification rank to which all
organisms must be classified.
find more resources at oneclass.com
find more resources at oneclass.com
3
➢ In an evolutionary context, the species concept has been discussed extensively and
there is no single definition that is agreed upon. The biological species concept
emphasises reproductive isolation and the general lack or reduction of interbreeding
between sexually reproductive species
❖ 4
➢ Five kingdoms of cellular organisms have been recognised but classification schemes
are changing as phylogenetic relationships and monophyletic groups are discovered.
➢ With the recognition of two major evolutionary groups among the prokaryotes, they
are often classified as two super kingdoms or domains—Bacteria and Archaea.
➢ Eukaryotic organisms are grouped together as the super kingdom, or domain,
Eukarya. Eukarya includes four kingdoms: Protista, Plantae, Fungi and Animalia,
although Protista is not monophyletic.
➢
❖ 5
➢ Assuming that the rate of neutral mutations is constant, DNA sequence data may be
used as a molecular clock to date evolutionary divergences of organisms. However,
rates of evolution differ between genes and among lineages, and there is no universal
clock.
❖ 6
➢ protists are very diverse and are grouped together on whether they are autotrophic
or heterophics.
➢ photosynthetic protists were known as algae.
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Species are decreasing at a real fast rate due to human intervention biodiversity crisis. Endemic: have evolved at one place and occur nowhere else. Origin of life 3. 5 bn -4 bn yrs. ago. Phylogeny: pattern of branching depicting evolutionary relationships can be the basis for hypothesising how organisms have evolved. Cladistics analysis: comparative method of discovering the ordering on the branches of a phytogenic tree. Advanced character which are considered to have evolved more recently: apomorphic. Apomorphies: own unique characters due to evolutionary change after divergence similarities of early embryonic stages indicate that all vertebrates share a fundamental step in their developmental program. Modification of the later stages of development accounts for the great diversity of form within the vertebrates. Concept of homology: all life is based on the same fundamental principle. Unity believed that homologies existed between adult parts of animals as diverse as molluscs, insects and fishes,
