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Objectives
by the end of this unit you should be able to:
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Distinguish between pollen and spores
Define a pollen fingerprint
Classify the different organisms that produce pollen and spores
Compare and contrast the female and male reproductive parts in
plants
Distinguish between gymnosperms and angiosperms
Summarize the different methods of pollination and their
relevance in solving crimes
Identify the different ways pollen & spores are dispersed
State characteristics of pollen and spores that are important for
forensic studies
Summarize how pollen and spore evidence is collected at a crime
scene
Describe how pollen and spore samples are analyzed and
evaluated
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What type of evidence is pollen?
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What type of evidence is pollen?
 Trace evidence
 Circumstantial evidence
 Biological evidence
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What are two main factors that
investigators may be able to
determine by studying the pollen
or spores found on a victim/at a
crime scene?
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What are two main factors that
investigators may be able to
determine by studying the pollen
or spores found on a victim/at a
crime scene?
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Season in which the crime was
committed
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Geographic location of the crime
scene
Vocabulary words
pg. 107 in text, 10 minutes to complete
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Angiosperm
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Gymnosperm
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Palynology
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Forensic palynology
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Pollen “fingerprint”/Pollen profile
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Pollen grain
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Spore
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Pollination
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Stamen
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Pistil
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Exine
Vocabulary words
not in book
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Plant assemblage – a recognizable assemblage of
plant species occurring in a given geographic
region and are distinct from adjacent
assemblages.
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Datum point* – A specific, fixed location from
which all measurements on a site are made or to
which they are calibrated.
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Subdatum point* – Fixed locations measured
with respect to the datum point with the purpose
of mapping out an area for searching.
*used when investigatingburial sites.
How do forensic scientists determine where a
crime occurred if the body was moved from the
scene of the crime?
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Trace evidence
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Plant material can provide clues about a where a
crime occurred (geographic location).
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Plant material can also provide clues about
when a crime occurred (season, time of day).
Specialized forensic fields
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Forensic botany – study of plants and plant
ecology to help solve a crime.
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Forensic palynology – a subdivision of botany;
study of pollen and spore evidence to help
solve a crime.
How do forensic scientists determine where a
crime occurred if the body was moved from the
scene of the crime?
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A pollen grain is the male gamete of a seed
plant.
A spore is a reproductive cell that can grow
into a new organism without uniting with
another cell.
Locard’s principle of exchange
relative to pollen/spores:
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The transfer of pollen or spores
between a victim & suspect and/or a
crime scene.
Pollen “fingerprint”
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The number and type of pollen grains found in a
geographic area at a particular time of year.
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By understanding pollen production patterns for plants
in a given area, one can predict the pollen “fingerprint”
they would expect in samples from that area.
Plants
Nonseed vs seed plants
Nonseed
Seed
Ferns
Mosses
Liverworts
Horsetails
Club mosses
Gymnosperms:
Cycads
Ginkgoes
Conifers
Angiosperms
(flowering plants)
Cladogram of plant groups
Cone-bearing
plants
Ferns and
their relatives
Mosses and
their relatives
Flowers; Seeds
Enclosed in Fruit
Seeds
Water-Conducting
(Vascular) Tissue
Green algae
ancestor
Flowering
plants
Plant diversity
Cone-bearing plants
760 species
Ferns and
their relatives
11,000 species
Mosses and
their relatives
15,600 species
Flowering
plants
235,000 species