strategies of life - nd.edunsl/lectures/phys10062/chapter 20.pdfliving things use many different...
TRANSCRIPT
Strategies of Life
Chapter 20 Great Idea:
Living things use many different strategies to deal with the problems of acquiring and using matter and
energy
h"p://www.youtube.com/watch?v=uBuPiC3ArL8
h"p://www.youtube.com/watch?v=fIOUD1XFBeA
h"p://www.youtube.com/watch?v=HE6XUcq4g38 AgouL and Brazil nuts
Chapter Outline • The Organization of Living Things • What is Life? • Classifying Living Things • Survival: A New Look at the Life Around
You • Strategies of Fungi • Strategies of Plants • Strategies of Animals
Ways of Thinking about Living Things
• Levels – Biosphere – Ecosystem – Community – Population – Organism – Anatomy and physiology – Cellular – Molecular
• All levels complement each other
The Characteristics of Life • High degree of order and complexity • Part of larger systems of matter and energy • Life depends on chemical reactions in cells • Life requires liquid water • Organisms grow and develop • Regulate energy use • Share same genetic code, code is heritable • All living things are descended from a common
ancestor
EvoluLon
Chapter 25
Great Idea: All life on Earth evolved from single-celled organisms
by the process of natural selection.
h"p://www.youtube.com/watch?v=HE6XUcq4g38 EvoluLon of skin color
Chapter Outline • The Fact of Evolution • Chemical Evolution • Natural Selection and the Development
of Complex Life • The Evolution of Human Beings
The Fact of Evolution • Evolution – Ongoing process of change
• Scientists accept evolution as fact – Debate various theories
The Fossil Record • Fossils – Organism’s hard parts preserved
• Turned to rock • Replaced by minerals
• Fossil record – Fossils found, catalogued, and analyzed – Shows transitions – Incomplete
The Fossil Record – cont. • Three key ideas – Older fossils more different – Increasing complexity with time – Most species have gone extinct
The Biochemical Evidence
• DNA – Evidence for evolution – Changes slowly – Also compare amino acid sequences
• Cytochrome c – Humans and chimps identical – Rattlesnake 86% overlap
Evidence from Anatomy: Vestigial Organs
• Vestigial organs – Internal features – No useful function
• Examples – Appendix: humans – Wings: penguins – Hind legs: whales
Cataloging Life • Linnaean classification
– Shared characteristics
• Hierarchy – Kingdom – Phylum – Class – Order – Family – Genus – Species
• Binomial nomenclature
Different Division of Life
• Carl Woese – Molecular genetics – Three domains
• Bacteria • Archaea • Eucaryea
Classifying Human Beings
• Kingdom: Animals • Phylum: Chordates – Subphylum: vertebrates
• Class: Mammals • Order: Primates • Family: Hominid • Genus: Homo • Species: sapiens
The Characteristics of Life • High degree of order and complexity • Part of larger systems of matter and energy • Life depends on chemical reactions in cells • Life requires liquid water • Organisms grow and develop • Regulate energy use • Share same genetic code, code is heritable • All living things are descended from a common
ancestor
Implications of Linnaean Classification (physical similarities)
• Use of DNA • Similarity depends on time and change • Classification results from real events
Survival: A New Look at the Life around You
• Autotrophs • Heterotrophs • Dealing with complexity- specialized
organs vs. collection of similar cells • Two basic tasks of life – Obtain and distribute molecules for energy – Reproduce
Strategies of Fungi • Growth – Filaments – Decomposers
• Structure – Mass of filaments
• Reproduction – Break filaments – Asexual reproduction • Spores
The Simplest Plants • Phylum: Bryophytes • Structure – No roots – Photosynthetic
• Reproduction – Sexual – Asexual
Vascular Plants • Phylum: vascular plants • Structure – Roots, stems, leaves – Control water loss
• Reproduction – Seedless – Gymnosperms (seeds---no flowers) – Angiosperms (flowers and seeds) • Sexual and asexual
• The Brazil nut is a hard shelled seed from the Brazil nut tree. The Brazil nut tree, also known as the castana tree, is from the Neotropics, spread out from southern Mexico into southern Brazil. The Brazil nut represents only a single species in of the genus BertholleLa. Although there is considerable variaLon in fruit size and shape and number of seeds per fruit, there is no jusLficaLon for recognizing more than one species of BertholleLa.
• It is the only species in the genus BertholleLa and can be found in the Amazon forests of Brazil, Bolivia, Peru, Columbia, the Guianas, and Venezuela. The Brazil nut tree reach heights of about 150 feet, their trunk can be about 8 feet in diameter and can live about 500 years. This tremendous tree only has branches and leaves at the top third of the tree. The branches can span a hundred feet providing a canopy over other rain forest vegetaLon. The leaves of the Brazil nut tree are long, green and waxy. At the end of the leaf is a yellow orchid. This flower, when pollinated, produces the fruit that contain the Brazil nuts.
• Flowering happens during the dry season and conLnues into the wet season. Dry season is very important for Brazil nuts, they grow naturally only in areas with a 4-‐month dry season. In the eastern part of Amazonian Brazil, the flowering starts near the end of the rainy season in September and runs into February. October, November, and December are when the Peak flowering happens.
• Cross-‐pollinaLon is required for seed set in Neotropical Lecythidaceae. The Brazil Nut tree depends on bees, and bats to pollinate the flowers and begin the fruit and seed development of Lecythidaceae.
• The large shelled fruit, similar to a coconut, takes about 14 months to mature. The fruit is about 4-‐6 inches in diameter and can weigh up to 4 pounds. The shell of the fruit is about a quarter of an inch thick and inside clustered together are between 12-‐24 brazil nuts.
• Brazil nuts are primarily harvested from wild trees during six month period in the rainy season. The fruits weigh between 0.5 to 2.5 kilograms and contain about 20 seeds. The brazil nut trees are so tall that harvesLng the fruits consists of gathering the fruit afer they fall. Once the fruit falls, it has to be gathered quickly since they are suscepLble to fungal a"ack, and animals also carry the fruit away.
h"p://youtu.be/fIOUD1XFBeA h"p://youtu.be/mZYmkd2FGUc
Brazil-‐Nut Tree Symbiosis Gregory Cello Rainforests are characterized by a unique vegetaLve structure consisLng of several verLcal layers including the overstory, canopy, understory, shrub layer, and ground level. One of the largest trees in the rainforest that makes up a large porLon of the canopy is the Brazil nut tree (Bertholle(a excelsa). These trees are dependent on several animal species for their survival such as the agouL, a ground-‐dwelling rodent, for a key part of their life cycle. The agouL is the only animal with teeth strong enough to open their grapefruit-‐sized seed pods. While the agouL eats some of the Brazil nut's seeds, it also sca"ers the seeds across the forest by burying caches far away from the parent tree. These seeds then germinate and form the next generaLon of trees. For pollinaLon, Brazil nut trees are dependent on Euglossine orchid bees. Without these large-‐bodied bees, Brazil nut reproducLon is not possible. For this reason, there has been li"le success growing Brazil nut trees in plantaLons as they only appear to grow in primary rainforest.
Invertebrates • Invertebrates – No backbone – Most diverse animals
• Arthropods – 70% of known animal species
• Structure – Exoskeleton
Vertebrates • Organization – Ocean to terrestrial
• Evolution – Earliest fish – Bony Fish – Amphibians – Reptiles – Birds – Mammals