Evolution
The history and science of origin and evolution comprise two events, the beginning of life and expansion of life. Our earth originated about 4.5 billion years ago. The term evolution is derived from two Latin words and means the act of unfolding or unrolling. English philosopher Herbert Spencer first used it. Evolution is defined as the change in heritable traits of biological populations over successive generations. These traits are the manifestations of genes that are passed down from parent to offspring during reproduction.
Cladistics
Cladistics is a technique in the classification of organisms, where they are grouped into different clades. The proof for the relationships that are hypothesized is based on the shared derived characteristics known as synapomorphies. These characteristics do not exist in many of the distant ancestors and groups. The common ancestor along with its descendants is considered to be a part of the clade. The rate of closeness is directly proportional to the cladistic grouping and is useful in analyzing the evolutionary mechanism.
Outgroups
Outgroups are significant in studying cladistics or phylogenetics (that describe the evolutionary relationship between different organisms). Further, it is also important to understand the differences and similarities between different organisms.
Taxonomy
It is the branch of biology that works with the identification of organisms at first, then naming, and classification of them into phenetic or phylogenetic groups (a classification system). In other words, it is the scientific study of biological diversity and a part of systematic biology.
Phylogenetics
Phylogenetics is the scientific study of how various groups of organisms are related at the evolutionary level. It finds the relationship between various organisms based on their evolutionary similarities and differences. It is a part of the taxonomy. Although the taxonomic study is not only concerned about phylogeny but taxonomic studies are also concerned about the classification and nomenclature of the different individuals from different taxon.
1. Draw a simplified cladogram that includes only the orders. Based the cladogram in the image below.
![females: whorls of megasporophylls
at trunk apex alternate with trophophylls
(no seed cones)
Cycadaceae
pachycaulous; pinnate megaphylls
males with pollen cones; pollen tube simple
roots with N2-fixing cyanobacteria
seed cones with 2[3] seeds
per megasporophyll
CYCADALES
lignins with syringaldehydes Zamiaceae
dioecious
stout short shoots with
Ivs flabelliform, dichotomously veined, deciduous
pollen tube branched
ovules 2 (basal collar); cotyledons 2
zooidogamy
GINKGOALES
Ginkgoaceae
xeromorphic, Ivs scale-like, sheathed, shed early
stems narrow, striate, photosynthetic
seed cones: 1-3 ovules; double fertilization
Ephedraceae
ovules/seeds not
enclosed by carpel
vessels
porose perforation plates
dioecious
caudex
Ivs 2 (straplike) life-long basal continuous growth
venation parallel
9 gametophyte tubes grow towards pollen tubes
pollen tube haustorial
primarily
anemophilous
primary endosperm
no bisexual strobili
Welwitschiaceae
GNETALES
striate pollen
binucleate sperm
cotyledons 2
ectomycorrhizal
Ivs opposite, simple, broad,
venation reticulate
(angiosperm-like "convergence")
laticifers
Gnetaceae
monoecious
resin canals; Ivs linear (needles)
pollen mostly 2-saccate
ovules 2, inverted
seeds winged
PINALES
Pinaceae
loss of
monoecious or dioecious
spermatozoids
Conifers I
Ivs broad to acicular
nucellar
siphonogamy
pollen not saccate
seed cones large, disintegrate
cotyledons 2-4
Araucariaceae
leaves
morphologically
diverse
dioecious; roots with nodules
1 ovule/scale, cone often one seeded
receptacle and/or
opimatium/carpidium fleshy
cotyledons 2
Podocarpaceae
Seed
Plants
CUPRESSALES
monoecious
"double needles" (cladodes)
ovules 7-9
Sciadopityaceae
eustele
secondary growth
heterosporous
Conifers I|
dioecious
ovules
seeds
pollen
pollen tube with 2 gametes each
evergreen; pollen cones tiny
peltate microsporangiophores
1 ovule, 1 seed/cone, arillate
cotyledons 2
Тахасeae
monoecious
(Juniperus: monoecious or dioecious)
Ivs mostly scale-like
pollen not saccate
ovules 1-20/scale
cotyledons many
seed cones terminal
cone scales
opposite
Cupressaceae
bisexual flower; fruit (ovules enclosed by carpel); loss of spermatozoids
pollen tube penetrating stigma/style/nucellus/synergid (complete siphonogamy)
vessels; pollenkitt; primarily zoophilous
double fertilization: triploid endosperm
ANGIOSPERMS SEE ANGIOSPERM PHYLOGENY POSTER
Jorcität
ARorlin
dng
Spermatophytes
Gymnosperms](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2Fd8dc393c-f7c4-495f-aaeb-919425d33078%2F75bfabdf-6011-4fee-a8c6-a5965a6c799a%2Fyc8t7hr_processed.jpeg&w=3840&q=75)
Step by step
Solved in 3 steps with 1 images
