3. WHAT IS EMBRYOLOGY?
Embryology, the study of the development of the anatomy of an organism
to its adult form, provides evidence for evolution as embryo formation in
widely-divergent groups of organisms tends to be conserved. Structures that
are absent in the adults of some groups often appear in their embryonic
forms, disappearing by the time the adult or juvenile form is reached. For
example, all vertebrate embryos, including humans, exhibit gill slits and tails
at some point in their early development.These disappear in the adults of
terrestrial groups, but are maintained in adults of aquatic groups, such as fish
and some amphibians. Great ape embryos, including humans, have a tail
structure during their development that is lost by birth.
4.
5.
6. DEVELOPMENT OF EMBRYO
•Similarities in Early Development
•Homologous Structures
•Vestigial Structures
•Embryonic Recapitulation
•Comparative Embryology
•Evolutionary Conservation
7.
8. SIMILARITIES IN
EARLY
DEVELOPMENT
Embryos of different species
share common features during
early stages, indicating shared
ancestry. For example,
vertebrate embryos, including
humans, show similar structures
like pharyngeal pouches and
tails, reflecting their
evolutionary history.
9.
10. HOMOLOGOUS
STRUCTURES
Structures in embryos that lead
to different adult forms in
various species can be
homologous, showing
evolutionary connections. For
instance, vertebrates like
humans, birds, and bats have
forelimbs with a common
developmental origin, despite
their different functions.
11.
12. VESTIGITAL
STRUCTURES
Some embryos display
vestigial structures,
remnants of ancestral
features with lost functions.
Examples include
rudimentary gill slits in
human embryos,
reminiscent of our aquatic
ancestors.
13.
14. EMBRYONIC RECAPITULATION
Embryonic development retains ancestral
features that align with evolutionary
relationships.This concept, proposed by
Ernst Haeckel, suggests that the stages of
embryo development mirror the species'
evolutionary past.
15.
16. COMPARATIVE
EMBRYOLOGY
Studying embryos from
different species reveals
similarities and differences in
developmental processes.
Comparisons help scientists
infer evolutionary relationships
and understand the
evolutionary history of
organisms.
17. EVOLUTIONARY CONSERVATION
Evolutionarily conserved developmental genes
and pathways play crucial roles in embryonic
development across diverse organisms.The
presence of these shared genetic mechanisms
supports the idea of common ancestry and
evolutionary conservation of developmental
processes.
18. COMPARATIVE EMBRYOLOGY
EARLY EMBRYOS OFVARIOUS
ORGANISMS DEMONSTRATE
EVOLUTIONARY RELATIONSHIPS
AS DEVELOPMENT PROCEEDS,THE
TRAITS OF EACH SPECIES BECOME
MORE EVIDENT.
20. THE IMPORTANCE OF EMBRYOLOGY:
• Understanding development - Embryology helps us understand how
organisms grow and develop, from the simplest creatures to humans.
• Medical applications -This knowledge has numerous medical applications,
including assisted reproductive technologies, prenatal diagnosis of birth
defects, and regenerative medicine.
• Evolutionary insights - By studying the development of different species,
embryology can shed light on evolutionary relationships and the history of
life on Earth