IntelligentDesign/RandomDrift

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Andy Gardner; andyggardner@gmail.com, aggardner@rhodes.edu; husband / evolutionary biologist / teacher / espresso-obsessive / car nut / etc.

ichthyologist:

Sundew Catapults Prey into Trap

Drosera glanduligera is a species of sundew, a group of carnivorous plants that use sticky tentacles to ensnare their prey. This is species is unique in that it has extremely fast ‘snap tentacles’ which literally fling their prey into their sticky traps.

Sundews have evolved the ability to digest insects as an adaptation to their nutrient poor habitats. Once a prey is caught in the glue-like secretions, it either dies from exhaustion or asphyxiates from being smothered in dew. The plant then secretes enzymes which break down the insect, allowing the plant to absorb its nutrients.

All species of sundew are able to move their inner tentacles to pass prey towards the center of the leaf, where digestion is most efficient. Many species are able to fold the surface of the leaf around the prey to ensure contact with a larger digestive surface.

Drosera glanduligera is the fastest moving sundew, with ‘snap tentacles’ which fold inwards within 75 milliseconds. This action is triggered when an insect makes contact with them, and are powerful enough to catapult the insect into the center of the leaf, where it becomes glued down. 

Gif from video: Poppinga, S. Et al. via Wikimedia Commons

(via science-junkie)

— 18 hours ago with 2470 notes
#professional  #teaching  #anatomy  #ecology  #drosera  #gif  #evolution 
science-junkie:

The Origin of Humans Is Surprisingly Complicated
Human family tree used to be a scraggly thing. With relatively few fossils to work from, scientists’ best guess was that they could all be assigned to just two lineages, one of which went extinct and the other of which ultimately gave rise to us. Discoveries made over the past few decades have revealed a far more luxuriant tree, however—one abounding with branches and twigs that eventually petered out. This newfound diversity paints a much more interesting picture of our origins but makes sorting our ancestors from the evolutionary dead ends all the more challenging.
Source: Scientific American

science-junkie:

The Origin of Humans Is Surprisingly Complicated

Human family tree used to be a scraggly thing. With relatively few fossils to work from, scientists’ best guess was that they could all be assigned to just two lineages, one of which went extinct and the other of which ultimately gave rise to us. Discoveries made over the past few decades have revealed a far more luxuriant tree, however—one abounding with branches and twigs that eventually petered out. This newfound diversity paints a much more interesting picture of our origins but makes sorting our ancestors from the evolutionary dead ends all the more challenging.

Source: Scientific American

— 18 hours ago with 1024 notes
#evolution  #teaching  #phylogeny  #human  #history  #professional 
Lechenaultia tubiflora from Wiliam Archer’s excellent blog
http://esperancewildflowers.blogspot.com.au/

Lechenaultia tubiflora from Wiliam Archer’s excellent blog

http://esperancewildflowers.blogspot.com.au/

— 2 days ago
#Lechenaultia  #plants  #australia  #professional  #goodeniaceae 
From Denoeud et al:
The coffee genome provides insight into the convergent evolution of caffeine biosynthesis
(A) The principal caffeine biosynthetic pathway. Three methylation steps are necessary to produce caffeine from xanthosine, involving the successive action of three NMTs: xanthosine methyltransferase (XMT), theobromine synthase [7-methylxanthine methyltransferase (MXMT)], and caffeine synthase [3,7-dimethylxanthine methyltransferase (DXMT)]. SAM, S-adenosylmethionine; SAH, S-adenosylhomocysteine. (B) Evolutionary position of caffeine-producing plants with respect to other eudicots (phylogeny adapted fromwww.mobot.org/MOBOT/research/APweb/). (C) ML phylogeny of coffee, tea, and cacao NMTs. Bootstrap support values (percentages) from 1000 replicates are shown next to relevant clades. Branch lengths are proportional to expected numbers of nucleotide substitutions per site. Colors identify genes assignable to the genomic blocks denoted in (D). (D) (Left) A model summarizing the duplication history of coffee NMT genes, following the phylogeny in (C). Three distinct tandem gene arrays evolved in situ on chromosome 1 from nearby gene duplicates (bold squares). The red and green blocks, colored as in (C), translocated (to chromosome 9) or rearranged (to elsewhere on chromosome 1) from their ancestral locus (blue region), respectively. (Right) Gene orders on modern chromosomes. Translocation of the red block, containing the putative caffeine NMT metabolic cluster, left the phylogenetically derived CcDXMT gene behind. Similarly, CcNMT19is a derived gene within its own NMT clade that remained in place following movement of the green block. Numbers at branches indicate relative times since major duplication events or diversification times of the tandem arrays, calculated from approximately neutral synonymous substitution rates. (E) Expression profiles (reads per kilobase per million reads mapped) of known Coffea canephoraNMTs. The genes in the putative metabolic cluster (along with CcDXMT and CcMXMT) exhibit similar expression patterns, higher in perisperm than endosperm. Data are plotted as log2 values. DAP, days after pollination.

From Denoeud et al:

The coffee genome provides insight into the convergent evolution of caffeine biosynthesis

(A) The principal caffeine biosynthetic pathway. Three methylation steps are necessary to produce caffeine from xanthosine, involving the successive action of three NMTs: xanthosine methyltransferase (XMT), theobromine synthase [7-methylxanthine methyltransferase (MXMT)], and caffeine synthase [3,7-dimethylxanthine methyltransferase (DXMT)]. SAM, S-adenosylmethionine; SAH, S-adenosylhomocysteine. (B) Evolutionary position of caffeine-producing plants with respect to other eudicots (phylogeny adapted fromwww.mobot.org/MOBOT/research/APweb/). (C) ML phylogeny of coffee, tea, and cacao NMTs. Bootstrap support values (percentages) from 1000 replicates are shown next to relevant clades. Branch lengths are proportional to expected numbers of nucleotide substitutions per site. Colors identify genes assignable to the genomic blocks denoted in (D). (D) (Left) A model summarizing the duplication history of coffee NMT genes, following the phylogeny in (C). Three distinct tandem gene arrays evolved in situ on chromosome 1 from nearby gene duplicates (bold squares). The red and green blocks, colored as in (C), translocated (to chromosome 9) or rearranged (to elsewhere on chromosome 1) from their ancestral locus (blue region), respectively. (Right) Gene orders on modern chromosomes. Translocation of the red block, containing the putative caffeine NMT metabolic cluster, left the phylogenetically derived CcDXMT gene behind. Similarly, CcNMT19is a derived gene within its own NMT clade that remained in place following movement of the green block. Numbers at branches indicate relative times since major duplication events or diversification times of the tandem arrays, calculated from approximately neutral synonymous substitution rates. (E) Expression profiles (reads per kilobase per million reads mapped) of known Coffea canephoraNMTs. The genes in the putative metabolic cluster (along with CcDXMT and CcMXMT) exhibit similar expression patterns, higher in perisperm than endosperm. Data are plotted as log2 values. DAP, days after pollination.

— 1 week ago
#coffee  #science  #caffeine  #evolution  #phylogeny  #professional 
The Holotypic Occlupanid Research Group
http://www.horg.com/horg/

The Holotypic Occlupanid Research Group

http://www.horg.com/horg/

— 1 week ago
#taxonomy  #science  #biology  #professional 
likeafieldmouse:

Paul Klee - Architecture of the Plain (1923)

likeafieldmouse:

Paul Klee - Architecture of the Plain (1923)

(via moonmoth)

— 4 weeks ago with 1677 notes
#klee  #art  #quilt? 

infinity-imagined:

A hypothesized mechanism for the origin of life, an event called abiogenesis.  In this version, called RNA world, small molecules called nucleotides formed in the waters of the early Earth during the Hadean Eon, and polymerized on the surface of clay minerals.  These simple chains of RNA could replicate themselves in solution, but only slowly and inaccurately.  An RNA molecule developed which would fold into a structure that catalyzed RNA polymerization; a ribozyme.  The first ribozymes would replicate their sister strands, and produce copies of themselves and other RNA molecules. 

     In the same environment, long chains of carbon molecules called phospholipids were formed.  These molecules have two parts, the tail, which is hydrophobic, and the head, which is hydrophillic.  Because of these properties phospholipids will stick together and form micelles and vesicles in water.  Vesicles can absorb RNA nucleotides, concentrating them and creating a space where they can replicate, mutate and evolve.  At some point a ribozyme became enclosed within a vesicle, starting a chain reaction that evolved into the multitude of biological forms that we see today.

   Because this event occurred more than 3.8 billion years ago, theories about how and where it happened are highly speculative.  Possible environments for abiogensis include hydrothermal vents on the ocean floor, hyper saline bubbles of water trapped in ice, radioactive lakes or lagoons on earths surface, and even in space or on another planet, brought to earth through a panspermia event.  We have very little molecular evidence of the first cells, but ribozymes and catalytic RNA molecules are embedded in the DNA replication machinery of all life.  Because evidence of this event has almost certainly been lost to time, the true mechanisms of the origin of life may remain a mystery to science.

(Source: exploringorigins.org, via mrcaptaincook)

— 4 weeks ago with 4428 notes
#abiogenesis  #evolution  #teaching  #science  #gif  #art  #DNA  #cell  #cell division  #professional 
Goodeniaceae Working Group Symposium Western Australian Herbarium, Perth Fourth of August, 2014. 

Goodeniaceae Working Group Symposium
Western Australian Herbarium, Perth
Fourth of August, 2014. 

— 1 month ago
#professional  #australia  #goodeniaceae  #friends 
Xanthorrhoea, grass tree, at Royal NP.

Xanthorrhoea, grass tree, at Royal NP.

— 1 month ago with 4 notes
#Xanthorrhoea  #grass tree  #australia  #photography  #plants